Re: [Bf-committers] Blender tangent space calculation
Correct, this is how blender does it everywhere in its code-base. Ok. I've asked because after weldind I've gotten this problem with some quads. But today seems that I solve it by swapping the first vertex in the vert array with the first finded vertex that is not indexed to any of the 4'th face's index. On Sat, Nov 19, 2011 at 1:13 AM, Morten Mikkelsen mikkels...@gmail.comwrote: I wanted to ask about this line: const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; Or there is no way that last index points to zero? Correct, this is how blender does it everywhere in its code-base. Super glad to hear you're getting useful results! Be sure to submit a patch for review. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
Be sure to submit a patch for review. I've submitted a patch today. This is my first patch and I hope I've did all right. I've checked it for warnings, added txt file with small description about api. I've added a simple test exporting script that writes a data to txt file. I've added a 'weldmesh.h' and 'weldmesh.c' too. And also added the blend file with a simple mesh and generated normal map. http://projects.blender.org/tracker/index.php?func=detailaid=29335group_id=9atid=127 I'll be very grateful if someone's find a time to test it. Thanks :) On Sat, Nov 19, 2011 at 8:27 PM, Eugene Minov minov@gmail.com wrote: Correct, this is how blender does it everywhere in its code-base. Ok. I've asked because after weldind I've gotten this problem with some quads. But today seems that I solve it by swapping the first vertex in the vert array with the first finded vertex that is not indexed to any of the 4'th face's index. On Sat, Nov 19, 2011 at 1:13 AM, Morten Mikkelsen mikkels...@gmail.comwrote: I wanted to ask about this line: const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; Or there is no way that last index points to zero? Correct, this is how blender does it everywhere in its code-base. Super glad to hear you're getting useful results! Be sure to submit a patch for review. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
I am not 100% sure I understand you correctly but your fix doesn't sound correct but perhaps I am misunderstanding you. Anyway, the welder is going to generate a zero based index list unlike what is used within Blender. If you want to use the indexed result within a Blender context you'd have to put a dummy vertex at the beginning of the vertex array such that all other vertices are offset by one entry and then you'd add all the welder-generated indices by +1 to offset to after the dummy vertex. This way triangles can still have their fourth index as 0 which points to the dummy vertex and within Blender means no vertex assigned. On Sat, Nov 19, 2011 at 9:27 AM, Eugene Minov minov@gmail.com wrote: Correct, this is how blender does it everywhere in its code-base. Ok. I've asked because after weldind I've gotten this problem with some quads. But today seems that I solve it by swapping the first vertex in the vert array with the first finded vertex that is not indexed to any of the 4'th face's index. On Sat, Nov 19, 2011 at 1:13 AM, Morten Mikkelsen mikkels...@gmail.com wrote: I wanted to ask about this line: const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; Or there is no way that last index points to zero? Correct, this is how blender does it everywhere in its code-base. Super glad to hear you're getting useful results! Be sure to submit a patch for review. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
If you want to use the indexed result within a Blender context you'd have to put a dummy vertex at the beginning of the vertex array such that all other vertices are offset by one entry I mean put a dummy vertex in front of the unique vertices of course (meaning after welding). And also +1 to the indices you get after welding. On Sat, Nov 19, 2011 at 12:35 PM, Morten Mikkelsen mikkels...@gmail.comwrote: I am not 100% sure I understand you correctly but your fix doesn't sound correct but perhaps I am misunderstanding you. Anyway, the welder is going to generate a zero based index list unlike what is used within Blender. If you want to use the indexed result within a Blender context you'd have to put a dummy vertex at the beginning of the vertex array such that all other vertices are offset by one entry and then you'd add all the welder-generated indices by +1 to offset to after the dummy vertex. This way triangles can still have their fourth index as 0 which points to the dummy vertex and within Blender means no vertex assigned. On Sat, Nov 19, 2011 at 9:27 AM, Eugene Minov minov@gmail.com wrote: Correct, this is how blender does it everywhere in its code-base. Ok. I've asked because after weldind I've gotten this problem with some quads. But today seems that I solve it by swapping the first vertex in the vert array with the first finded vertex that is not indexed to any of the 4'th face's index. On Sat, Nov 19, 2011 at 1:13 AM, Morten Mikkelsen mikkels...@gmail.com wrote: I wanted to ask about this line: const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; Or there is no way that last index points to zero? Correct, this is how blender does it everywhere in its code-base. Super glad to hear you're getting useful results! Be sure to submit a patch for review. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
If you want to use the indexed result within a Blender context you'd have to put a dummy vertex at the beginning of the vertex array such that all other vertices are offset by one entry and then you'd add all the welder-generated indices by +1 to offset to after the dummy vertex. Yes you're right! My first thought was to fix this in the same way. Seems that I just wanted to find a way to not allocate an extra dummy vertex :) Actually I doing this, I put a dummy vertex at the beginning and then do +1 to the indices. But only if I cannot find another appropriate vertex within other unique vertices in the array, on which didn't point any fourth index from any face. There's almost always must be that vertex. Then if I find this vertex I swap it with a vertex at the begining. Then I loop all my indexes and change indexes that point to fonded vertex, to '0', and otherwise, those indexes that point to '0', i change to index of founded vertex. I've tested this on a diferent meshes, wached results and I pretty sure that it must work correct, but now I think that maybe it'd be better and easier to put an extra vertex only :) On Sat, Nov 19, 2011 at 11:36 PM, Morten Mikkelsen mikkels...@gmail.comwrote: If you want to use the indexed result within a Blender context you'd have to put a dummy vertex at the beginning of the vertex array such that all other vertices are offset by one entry I mean put a dummy vertex in front of the unique vertices of course (meaning after welding). And also +1 to the indices you get after welding. On Sat, Nov 19, 2011 at 12:35 PM, Morten Mikkelsen mikkels...@gmail.com wrote: I am not 100% sure I understand you correctly but your fix doesn't sound correct but perhaps I am misunderstanding you. Anyway, the welder is going to generate a zero based index list unlike what is used within Blender. If you want to use the indexed result within a Blender context you'd have to put a dummy vertex at the beginning of the vertex array such that all other vertices are offset by one entry and then you'd add all the welder-generated indices by +1 to offset to after the dummy vertex. This way triangles can still have their fourth index as 0 which points to the dummy vertex and within Blender means no vertex assigned. On Sat, Nov 19, 2011 at 9:27 AM, Eugene Minov minov@gmail.com wrote: Correct, this is how blender does it everywhere in its code-base. Ok. I've asked because after weldind I've gotten this problem with some quads. But today seems that I solve it by swapping the first vertex in the vert array with the first finded vertex that is not indexed to any of the 4'th face's index. On Sat, Nov 19, 2011 at 1:13 AM, Morten Mikkelsen mikkels...@gmail.com wrote: I wanted to ask about this line: const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; Or there is no way that last index points to zero? Correct, this is how blender does it everywhere in its code-base. Super glad to hear you're getting useful results! Be sure to submit a patch for review. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
Hi! I think that I've finished this. Don't forget to look in do_multires_bake() in object_bake.c It shows you how to add the tangent layer: Yes, I've figured out how to create DerivedMesh object by Mesh object. And then I've created the tangent layer in this way. // get pointer to the already generated tangents pvtangent= DM_get_face_data_layer(dm, CD_TANGENT); But if mesh don't have a tex-coords, 'pvtangent' anyway is NULL For this case I weld normals only. I tried to export a mesh with tangents and normals into my app and seems that normal map looking correct. const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; On Thu, Nov 17, 2011 at 8:33 PM, Morten Mikkelsen mikkels...@gmail.comwrote: And flush_pixel() shows you how to traverse the buffer. Essentially the way it works in blender is there's always 4 of them per face whether it's a triangle or a quad. On Thu, Nov 17, 2011 at 9:31 AM, Morten Mikkelsen mikkels...@gmail.com wrote: Don't forget to look in do_multires_bake() in object_bake.c It shows you how to add the tangent layer: float *pvtangent= NULL; // create tangent vectors if not already created if(CustomData_get_layer_index(dm-faceData, CD_TANGENT) == -1) DM_add_tangent_layer(dm); // get pointer to the already generated tangents pvtangent= DM_get_face_data_layer(dm, CD_TANGENT); On Thu, Nov 17, 2011 at 8:49 AM, Eugene Minov minov@gmail.com wrote: The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c Okay, I've found a 'multiresbake_get_normal' function for correct normals calculation. I also looked into 'DM_add_tangent_layer' function in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c According to it, the tangent layer is filling by tangents when created. So I do need only to access and welding them and normals? That's good if so. Today I had time to try understand how RNA's works. And I almost create and test python interface with collections for faces and indexed vertices with normals and tangents in it. Hopefully soon I'll start welding. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. Okay, good one, I think I'll use it :) Thanks! On Wed, Nov 16, 2011 at 8:43 PM, Morten Mikkelsen mikkels...@gmail.com wrote: Sorry for confusing you here but I think I found a better reference for you since you'll be needing the tangents too and you are not supposed to be building them yourself. The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c do_multires_bake() These are being fetched after the line: float *pvtangent= NULL; These are then read in the function flush_pixel() including the normal which is fetched from there using multiresbake_get_normal() which as you can see looks a lot like the GetNormal() function I pointed you to in DerivedMesh.c. Anyway, definitely use this file as your reference. I should have shown you this one from the beginning. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. On Wed, Nov 16, 2011 at 5:32 AM, Eugene Minov minov@gmail.com wrote: If you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. Ok! Sounds good to me :) So right now I in progress of checkout latest svn sources and compile blender. (had problems with net) Then first of I'll try to create test version of python/C interface. I've not decided yet what names I'll use for it. And finally will be trying to implement it looking in DerivedMesh.c, I think that it's realy are a good example. If or when I have a problem, I'll be glad to use your help :) Many thanks for your kind cooperation! On Tue, Nov 15, 2011 at 10:41 PM, Morten Mikkelsen mikkels...@gmail.com wrote: I don't know anything about Python but if you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. On Tue, Nov 15, 2011 at 10:43 AM, Eugene Minov minov@gmail.com wrote: Yes, I absolutely agree, hard faces obviously must be
Re: [Bf-committers] Blender tangent space calculation
Sorry for extra line :) I wanted to ask about this line: const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; I think 'iGetNrVerts' may be incorrect with some cases when there is four vertices per face but the last one is points to first indexed vertex. Or there is no way that last index points to zero? On Fri, Nov 18, 2011 at 9:48 PM, Eugene Minov minov@gmail.com wrote: Hi! I think that I've finished this. Don't forget to look in do_multires_bake() in object_bake.c It shows you how to add the tangent layer: Yes, I've figured out how to create DerivedMesh object by Mesh object. And then I've created the tangent layer in this way. // get pointer to the already generated tangents pvtangent= DM_get_face_data_layer(dm, CD_TANGENT); But if mesh don't have a tex-coords, 'pvtangent' anyway is NULL For this case I weld normals only. I tried to export a mesh with tangents and normals into my app and seems that normal map looking correct. const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; On Thu, Nov 17, 2011 at 8:33 PM, Morten Mikkelsen mikkels...@gmail.comwrote: And flush_pixel() shows you how to traverse the buffer. Essentially the way it works in blender is there's always 4 of them per face whether it's a triangle or a quad. On Thu, Nov 17, 2011 at 9:31 AM, Morten Mikkelsen mikkels...@gmail.com wrote: Don't forget to look in do_multires_bake() in object_bake.c It shows you how to add the tangent layer: float *pvtangent= NULL; // create tangent vectors if not already created if(CustomData_get_layer_index(dm-faceData, CD_TANGENT) == -1) DM_add_tangent_layer(dm); // get pointer to the already generated tangents pvtangent= DM_get_face_data_layer(dm, CD_TANGENT); On Thu, Nov 17, 2011 at 8:49 AM, Eugene Minov minov@gmail.com wrote: The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c Okay, I've found a 'multiresbake_get_normal' function for correct normals calculation. I also looked into 'DM_add_tangent_layer' function in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c According to it, the tangent layer is filling by tangents when created. So I do need only to access and welding them and normals? That's good if so. Today I had time to try understand how RNA's works. And I almost create and test python interface with collections for faces and indexed vertices with normals and tangents in it. Hopefully soon I'll start welding. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. Okay, good one, I think I'll use it :) Thanks! On Wed, Nov 16, 2011 at 8:43 PM, Morten Mikkelsen mikkels...@gmail.com wrote: Sorry for confusing you here but I think I found a better reference for you since you'll be needing the tangents too and you are not supposed to be building them yourself. The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c do_multires_bake() These are being fetched after the line: float *pvtangent= NULL; These are then read in the function flush_pixel() including the normal which is fetched from there using multiresbake_get_normal() which as you can see looks a lot like the GetNormal() function I pointed you to in DerivedMesh.c. Anyway, definitely use this file as your reference. I should have shown you this one from the beginning. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. On Wed, Nov 16, 2011 at 5:32 AM, Eugene Minov minov@gmail.com wrote: If you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. Ok! Sounds good to me :) So right now I in progress of checkout latest svn sources and compile blender. (had problems with net) Then first of I'll try to create test version of python/C interface. I've not decided yet what names I'll use for it. And finally will be trying to implement it looking in DerivedMesh.c, I think that it's realy are a good example. If or when I have a problem, I'll be glad to use your help :) Many thanks for your kind cooperation! On Tue, Nov 15, 2011 at 10:41 PM, Morten Mikkelsen mikkels...@gmail.com wrote: I don't know
Re: [Bf-committers] Blender tangent space calculation
I wanted to ask about this line: const int iGetNrVerts= data-mface[face_num].v4!=0 ? 4 : 3; Or there is no way that last index points to zero? Correct, this is how blender does it everywhere in its code-base. Super glad to hear you're getting useful results! Be sure to submit a patch for review. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c Okay, I've found a 'multiresbake_get_normal' function for correct normals calculation. I also looked into 'DM_add_tangent_layer' function in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c According to it, the tangent layer is filling by tangents when created. So I do need only to access and welding them and normals? That's good if so. Today I had time to try understand how RNA's works. And I almost create and test python interface with collections for faces and indexed vertices with normals and tangents in it. Hopefully soon I'll start welding. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. Okay, good one, I think I'll use it :) Thanks! On Wed, Nov 16, 2011 at 8:43 PM, Morten Mikkelsen mikkels...@gmail.comwrote: Sorry for confusing you here but I think I found a better reference for you since you'll be needing the tangents too and you are not supposed to be building them yourself. The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c do_multires_bake() These are being fetched after the line: float *pvtangent= NULL; These are then read in the function flush_pixel() including the normal which is fetched from there using multiresbake_get_normal() which as you can see looks a lot like the GetNormal() function I pointed you to in DerivedMesh.c. Anyway, definitely use this file as your reference. I should have shown you this one from the beginning. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. On Wed, Nov 16, 2011 at 5:32 AM, Eugene Minov minov@gmail.com wrote: If you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. Ok! Sounds good to me :) So right now I in progress of checkout latest svn sources and compile blender. (had problems with net) Then first of I'll try to create test version of python/C interface. I've not decided yet what names I'll use for it. And finally will be trying to implement it looking in DerivedMesh.c, I think that it's realy are a good example. If or when I have a problem, I'll be glad to use your help :) Many thanks for your kind cooperation! On Tue, Nov 15, 2011 at 10:41 PM, Morten Mikkelsen mikkels...@gmail.com wrote: I don't know anything about Python but if you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. On Tue, Nov 15, 2011 at 10:43 AM, Eugene Minov minov@gmail.com wrote: Yes, I absolutely agree, hard faces obviously must be exported in the same way how they seen in render. I think they can welds along with tangents. On Tue, Nov 15, 2011 at 9:01 PM, Morten Mikkelsen mikkels...@gmail.com wrote: There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c and you can see how it uses the averaged normal if the face is set to smooth and it uses the face normal which it calculates itself if the face is set to flat. If you are going to make an api to export tangents I for one cannot emphasize enough that I prefer an all or nothing solution. Either do it right or don't do it at all. The last thing we need is to introduce a new tangent space standard within blender. Either export the correct basis that was used for baking (this includes the normal) or don't try to do it at all. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers
Re: [Bf-committers] Blender tangent space calculation
Don't forget to look in do_multires_bake() in object_bake.c It shows you how to add the tangent layer: float *pvtangent= NULL; // create tangent vectors if not already created if(CustomData_get_layer_index(dm-faceData, CD_TANGENT) == -1) DM_add_tangent_layer(dm); // get pointer to the already generated tangents pvtangent= DM_get_face_data_layer(dm, CD_TANGENT); On Thu, Nov 17, 2011 at 8:49 AM, Eugene Minov minov@gmail.com wrote: The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c Okay, I've found a 'multiresbake_get_normal' function for correct normals calculation. I also looked into 'DM_add_tangent_layer' function in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c According to it, the tangent layer is filling by tangents when created. So I do need only to access and welding them and normals? That's good if so. Today I had time to try understand how RNA's works. And I almost create and test python interface with collections for faces and indexed vertices with normals and tangents in it. Hopefully soon I'll start welding. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. Okay, good one, I think I'll use it :) Thanks! On Wed, Nov 16, 2011 at 8:43 PM, Morten Mikkelsen mikkels...@gmail.com wrote: Sorry for confusing you here but I think I found a better reference for you since you'll be needing the tangents too and you are not supposed to be building them yourself. The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c do_multires_bake() These are being fetched after the line: float *pvtangent= NULL; These are then read in the function flush_pixel() including the normal which is fetched from there using multiresbake_get_normal() which as you can see looks a lot like the GetNormal() function I pointed you to in DerivedMesh.c. Anyway, definitely use this file as your reference. I should have shown you this one from the beginning. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. On Wed, Nov 16, 2011 at 5:32 AM, Eugene Minov minov@gmail.com wrote: If you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. Ok! Sounds good to me :) So right now I in progress of checkout latest svn sources and compile blender. (had problems with net) Then first of I'll try to create test version of python/C interface. I've not decided yet what names I'll use for it. And finally will be trying to implement it looking in DerivedMesh.c, I think that it's realy are a good example. If or when I have a problem, I'll be glad to use your help :) Many thanks for your kind cooperation! On Tue, Nov 15, 2011 at 10:41 PM, Morten Mikkelsen mikkels...@gmail.com wrote: I don't know anything about Python but if you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. On Tue, Nov 15, 2011 at 10:43 AM, Eugene Minov minov@gmail.com wrote: Yes, I absolutely agree, hard faces obviously must be exported in the same way how they seen in render. I think they can welds along with tangents. On Tue, Nov 15, 2011 at 9:01 PM, Morten Mikkelsen mikkels...@gmail.com wrote: There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c and you can see how it uses the averaged normal if the face is set to smooth and it uses the face normal which it calculates itself if the face is set to flat. If you are going to make an api to export tangents I for one cannot
Re: [Bf-committers] Blender tangent space calculation
And flush_pixel() shows you how to traverse the buffer. Essentially the way it works in blender is there's always 4 of them per face whether it's a triangle or a quad. On Thu, Nov 17, 2011 at 9:31 AM, Morten Mikkelsen mikkels...@gmail.comwrote: Don't forget to look in do_multires_bake() in object_bake.c It shows you how to add the tangent layer: float *pvtangent= NULL; // create tangent vectors if not already created if(CustomData_get_layer_index(dm-faceData, CD_TANGENT) == -1) DM_add_tangent_layer(dm); // get pointer to the already generated tangents pvtangent= DM_get_face_data_layer(dm, CD_TANGENT); On Thu, Nov 17, 2011 at 8:49 AM, Eugene Minov minov@gmail.com wrote: The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c Okay, I've found a 'multiresbake_get_normal' function for correct normals calculation. I also looked into 'DM_add_tangent_layer' function in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c According to it, the tangent layer is filling by tangents when created. So I do need only to access and welding them and normals? That's good if so. Today I had time to try understand how RNA's works. And I almost create and test python interface with collections for faces and indexed vertices with normals and tangents in it. Hopefully soon I'll start welding. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. Okay, good one, I think I'll use it :) Thanks! On Wed, Nov 16, 2011 at 8:43 PM, Morten Mikkelsen mikkels...@gmail.com wrote: Sorry for confusing you here but I think I found a better reference for you since you'll be needing the tangents too and you are not supposed to be building them yourself. The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c do_multires_bake() These are being fetched after the line: float *pvtangent= NULL; These are then read in the function flush_pixel() including the normal which is fetched from there using multiresbake_get_normal() which as you can see looks a lot like the GetNormal() function I pointed you to in DerivedMesh.c. Anyway, definitely use this file as your reference. I should have shown you this one from the beginning. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. On Wed, Nov 16, 2011 at 5:32 AM, Eugene Minov minov@gmail.com wrote: If you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. Ok! Sounds good to me :) So right now I in progress of checkout latest svn sources and compile blender. (had problems with net) Then first of I'll try to create test version of python/C interface. I've not decided yet what names I'll use for it. And finally will be trying to implement it looking in DerivedMesh.c, I think that it's realy are a good example. If or when I have a problem, I'll be glad to use your help :) Many thanks for your kind cooperation! On Tue, Nov 15, 2011 at 10:41 PM, Morten Mikkelsen mikkels...@gmail.com wrote: I don't know anything about Python but if you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. On Tue, Nov 15, 2011 at 10:43 AM, Eugene Minov minov@gmail.com wrote: Yes, I absolutely agree, hard faces obviously must be exported in the same way how they seen in render. I think they can welds along with tangents. On Tue, Nov 15, 2011 at 9:01 PM, Morten Mikkelsen mikkels...@gmail.com wrote: There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c
Re: [Bf-committers] Blender tangent space calculation
Sorry for confusing you here but I think I found a better reference for you since you'll be needing the tangents too and you are not supposed to be building them yourself. The proper way to get the tangent layer can be seen in: https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/editors/object/object_bake.c do_multires_bake() These are being fetched after the line: float *pvtangent= NULL; These are then read in the function flush_pixel() including the normal which is fetched from there using multiresbake_get_normal() which as you can see looks a lot like the GetNormal() function I pointed you to in DerivedMesh.c. Anyway, definitely use this file as your reference. I should have shown you this one from the beginning. If you need a free ultra simple welder there's one here -- http://jbit.net/~sparky/academic/welder/ You specify how many floats you have per vertex and it will weld for you. On Wed, Nov 16, 2011 at 5:32 AM, Eugene Minov minov@gmail.com wrote: If you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. Ok! Sounds good to me :) So right now I in progress of checkout latest svn sources and compile blender. (had problems with net) Then first of I'll try to create test version of python/C interface. I've not decided yet what names I'll use for it. And finally will be trying to implement it looking in DerivedMesh.c, I think that it's realy are a good example. If or when I have a problem, I'll be glad to use your help :) Many thanks for your kind cooperation! On Tue, Nov 15, 2011 at 10:41 PM, Morten Mikkelsen mikkels...@gmail.com wrote: I don't know anything about Python but if you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. On Tue, Nov 15, 2011 at 10:43 AM, Eugene Minov minov@gmail.com wrote: Yes, I absolutely agree, hard faces obviously must be exported in the same way how they seen in render. I think they can welds along with tangents. On Tue, Nov 15, 2011 at 9:01 PM, Morten Mikkelsen mikkels...@gmail.com wrote: There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c and you can see how it uses the averaged normal if the face is set to smooth and it uses the face normal which it calculates itself if the face is set to flat. If you are going to make an api to export tangents I for one cannot emphasize enough that I prefer an all or nothing solution. Either do it right or don't do it at all. The last thing we need is to introduce a new tangent space standard within blender. Either export the correct basis that was used for baking (this includes the normal) or don't try to do it at all. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
If it's not already available in the python API Hmm, I think not, as far as I can see in 'blender_python_reference_2_57' and by searching in 'blender-2.60a' sources. I've found only two files in sources with references to 'SMikkTSpaceContext' struct and to 'genTangSpaceDefault' function: - 'source/blender/blenkernel/intern/DerivedMesh.c' to get tangents for using in GLSL, I think; - 'source/blender/render/intern/source/convertblender.c' to get tangents for render's needs. But I not completely sure, I will look deeper. However, you'd need to supply support for normals as well since at this point the python API only gives access to the unconditionally averaged/smooth normals at the vertices. Ie. the api doesn't take faces set to soft/hard into account when submitting normals back to the script. Yes, I was wondering about that when started to write my own exporter since blender 2.49 :) But after I've found an 'EdgeSplit' modifier, I used to to export my meshes applied by it and to welding vertices and normals after. Maybe we'd can go a similar way and to provide tangents using averaged normals only?, since soft/hard edge's flags is 'de-facto' uses in that modifier only (as far as I know, even blender's render is not uses those flags). As about realization, I think it may be some analogue to the 'bpy.types.MeshTextureFace' class array, like 'MeshTangentFace' with four tangent vectors and fSign values for each vertex per face in it. Or with indexes to already welded ones. And generate data by request, in the 'Mesh.tangent_normals' accessor. Thanks. Eugene On Tue, Nov 15, 2011 at 4:02 AM, Morten Mikkelsen mikkels...@gmail.comwrote: So why not to simply adding possibility for generate/access a tangent normals into the python api? If it's not already available in the python API then I agree that it's a good idea. However, you'd need to supply support for normals as well since at this point the python API only gives access to the unconditionally averaged/smooth normals at the vertices. Ie. the api doesn't take faces set to soft/hard into account when submitting normals back to the script. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
Oh, I am sorry again, I'd thought that you mean soft/hard edges not faces, I stupid! :\ Yeah there is must me way to gen those normals too. On Tue, Nov 15, 2011 at 7:12 PM, Eugene Minov minov@gmail.com wrote: If it's not already available in the python API Hmm, I think not, as far as I can see in 'blender_python_reference_2_57' and by searching in 'blender-2.60a' sources. I've found only two files in sources with references to 'SMikkTSpaceContext' struct and to 'genTangSpaceDefault' function: - 'source/blender/blenkernel/intern/DerivedMesh.c' to get tangents for using in GLSL, I think; - 'source/blender/render/intern/source/convertblender.c' to get tangents for render's needs. But I not completely sure, I will look deeper. However, you'd need to supply support for normals as well since at this point the python API only gives access to the unconditionally averaged/smooth normals at the vertices. Ie. the api doesn't take faces set to soft/hard into account when submitting normals back to the script. Yes, I was wondering about that when started to write my own exporter since blender 2.49 :) But after I've found an 'EdgeSplit' modifier, I used to to export my meshes applied by it and to welding vertices and normals after. Maybe we'd can go a similar way and to provide tangents using averaged normals only?, since soft/hard edge's flags is 'de-facto' uses in that modifier only (as far as I know, even blender's render is not uses those flags). As about realization, I think it may be some analogue to the 'bpy.types.MeshTextureFace' class array, like 'MeshTangentFace' with four tangent vectors and fSign values for each vertex per face in it. Or with indexes to already welded ones. And generate data by request, in the 'Mesh.tangent_normals' accessor. Thanks. Eugene On Tue, Nov 15, 2011 at 4:02 AM, Morten Mikkelsen mikkels...@gmail.comwrote: So why not to simply adding possibility for generate/access a tangent normals into the python api? If it's not already available in the python API then I agree that it's a good idea. However, you'd need to supply support for normals as well since at this point the python API only gives access to the unconditionally averaged/smooth normals at the vertices. Ie. the api doesn't take faces set to soft/hard into account when submitting normals back to the script. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.chttps://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c and you can see how it uses the averaged normal if the face is set to smooth and it uses the face normal which it calculates itself if the face is set to flat. If you are going to make an api to export tangents I for one cannot emphasize enough that I prefer an all or nothing solution. Either do it right or don't do it at all. The last thing we need is to introduce a new tangent space standard within blender. Either export the correct basis that was used for baking (this includes the normal) or don't try to do it at all. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
Yes, I absolutely agree, hard faces obviously must be exported in the same way how they seen in render. I think they can welds along with tangents. On Tue, Nov 15, 2011 at 9:01 PM, Morten Mikkelsen mikkels...@gmail.comwrote: There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c and you can see how it uses the averaged normal if the face is set to smooth and it uses the face normal which it calculates itself if the face is set to flat. If you are going to make an api to export tangents I for one cannot emphasize enough that I prefer an all or nothing solution. Either do it right or don't do it at all. The last thing we need is to introduce a new tangent space standard within blender. Either export the correct basis that was used for baking (this includes the normal) or don't try to do it at all. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
Chiamami domani verso ora di pranzo al 3777074625 ora sono molto impegnato sto lavorando su una Correzione Colore E-Mail Sent via BlackBerry from BT Mobile -Original Message- From: Eugene Minov minov@gmail.com Sender: bf-committers-boun...@blender.org Date: Tue, 15 Nov 2011 21:43:12 To: bf-blender developersbf-committers@blender.org Reply-To: bf-blender developers bf-committers@blender.org Subject: Re: [Bf-committers] Blender tangent space calculation Yes, I absolutely agree, hard faces obviously must be exported in the same way how they seen in render. I think they can welds along with tangents. On Tue, Nov 15, 2011 at 9:01 PM, Morten Mikkelsen mikkels...@gmail.comwrote: There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c and you can see how it uses the averaged normal if the face is set to smooth and it uses the face normal which it calculates itself if the face is set to flat. If you are going to make an api to export tangents I for one cannot emphasize enough that I prefer an all or nothing solution. Either do it right or don't do it at all. The last thing we need is to introduce a new tangent space standard within blender. Either export the correct basis that was used for baking (this includes the normal) or don't try to do it at all. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
I don't know anything about Python but if you can get hold of the dm (DerivedMesh) on the c side of things then I can show you how to get the correct normals and tangents and even help you get them welded should you want this. On Tue, Nov 15, 2011 at 10:43 AM, Eugene Minov minov@gmail.com wrote: Yes, I absolutely agree, hard faces obviously must be exported in the same way how they seen in render. I think they can welds along with tangents. On Tue, Nov 15, 2011 at 9:01 PM, Morten Mikkelsen mikkels...@gmail.com wrote: There is no point in doing this unless you export the correct tangents and normals. That is the ones that were used to bake the normal map. I realize it blows that there is no API function to get the render normal. So what you have to do is produce it yourself like is done in DerivedMesh.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/source/blender/blenkernel/intern/DerivedMesh.c and many other places as well. An example in this file is the static function GetNormal() which is used as a call-back function by mikktspace.c and you can see how it uses the averaged normal if the face is set to smooth and it uses the face normal which it calculates itself if the face is set to flat. If you are going to make an api to export tangents I for one cannot emphasize enough that I prefer an all or nothing solution. Either do it right or don't do it at all. The last thing we need is to introduce a new tangent space standard within blender. Either export the correct basis that was used for baking (this includes the normal) or don't try to do it at all. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
I've said compilant as in I've tested with several meshes with automatic unwrapping (lots of seams) and baking from multires data and the result is perfect. I don't really know if it's really 100% compatible. I guess I must test with weird quads to be sure. In any case, I can tab - ctrl+t whenever I see a problem there. I'm just commenting that if you use ogre this shouldn't be an issue, but I completely agree that it should be a way to get exactly the same normals blender generates. 2011/11/15 Morten Mikkelsen mikkels...@gmail.com: You should be careful referring to them as compliant. I understand what you mean that they are compliant in format. But as is explained here -- http://wiki.blender.org/index.php/Dev:Shading/Tangent_Space_Normal_Maps the only way to be fully compliant is to use the exact same spaces that were used to generate the bake. This can also be achieved by using the referenced implementation (which is used in Blender) because it's designed to be order-independent and also independent of how the geometry is indexed or even indexed at all. Being fully compliant is what allows the renderer to achieve smooth transitions of normal fields going from one island to the next. This is important for characters especially. On Mon, Nov 14, 2011 at 8:34 AM, Alberto Torres kungfoo...@gmail.comwrote: In the last days I've been doing a blender-ogre material converter and after learning how each engine calculates the normals from tangent normal maps, I've found that Ogre::Mesh::buildTangentVectors builds the necessary vectors compatible with blender ones. It has a couple of options for splitting mirrored UVs and saving the polarity in the 4th component, just like blender's generated GLSL code expects. 2011/11/14 Eugene Minov minov@gmail.com: Hi! One more question, if I may. I've seen that there is a couple of the exporter programs which can generate tangents to export for specific 3D engines only, like OgreExporter. So why not to simply adding possibility for generate/access a tangent normals into the python api? I am not saying that it very hard to generate those tangents using Morten's implementation directly in program, but think it'll be more a.. consistence and ease way for people who building their games to properly export their meshes :) Maybe if nobody wants, then I'd like to try implement this by some time. What you guys think about this? Eugene On Mon, Nov 14, 2011 at 2:41 AM, Eugene Minov minov@gmail.com wrote: Oh, my bad :) I've seen that page but I'd thought this page is explains different baking modes in blender's render. Morten Mikkelsen - thank you for your great implementation! I'will learn it! M.G. Kishalmi - thanks for explanation ) On Mon, Nov 14, 2011 at 1:55 AM, M.G. Kishalmi l...@kishalmi.net wrote: Eugene, the link Morten pointed you to http://wiki.blender.org/index.php/Dev:Shading/Tangent_Space_Normal_Maps explains that the tangent space you created your normal maps in (in blender) is generated by the implementation in mikktspace.h https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.h and mikktspace.c https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.c . you might want to use those in your app (check the licence inside). cheers, lmg On Sun, Nov 13, 2011 at 10:51 PM, Eugene Minov minov@gmail.com wrote: Wow!! Thanks a lot, for pointing me to the google ;) But I afraid that maybe I've not correctly describe my problem. If so, sorry for that, because my english is still kinda weak. My problem not in generating a normal maps (a textures) in blender. Not at all. My problem is that I cannot fully correct render my already generated normal maps in my app. Because, how I mentioned in the last mail, the usual methods for this purpose (by UV coords) is not gives me desired results. So I wanted to ask for help with information about methods blender uses for generating tangents. And yes, I had searched in google but unfortunately have't found something helpful yet. If someone can point me to that kind of info, I will be very grateful! On Mon, Nov 14, 2011 at 12:08 AM, Morten Mikkelsen mikkels...@gmail.com wrote: There you go buddy -- http://lmgtfy.com/?q=blender+tangent+space On Sun, Nov 13, 2011 at 8:46 AM, Eugene Minov minov@gmail.com wrote: Hi. I am sorry if I subscribe into a wrong place, I am new and I've not actually planned to change or to debug the blender sources yet. But I trying to write app that'll be render models with normal mapping exported from blender, and I have a question about how exactly is blender calculates a tangent vectors when Unwrap operation in the editing mode performs?
Re: [Bf-committers] Blender tangent space calculation
Hi!
One more question, if I may.
I've seen that there is a couple of the exporter programs which can
generate tangents to export for specific 3D engines only, like OgreExporter.
So why not to simply adding possibility for generate/access a tangent
normals into the python api?
I am not saying that it very hard to generate those tangents using Morten's
implementation directly in program, but think it'll be more a.. consistence
and ease way for people who building their games to properly export their
meshes :)
Maybe if nobody wants, then I'd like to try implement this by some time.
What you guys think about this?
Eugene
On Mon, Nov 14, 2011 at 2:41 AM, Eugene Minov minov@gmail.com wrote:
Oh, my bad :) I've seen that page but I'd thought this page is explains
different baking modes in blender's render.
Morten Mikkelsen - thank you for your great implementation! I'will learn
it!
M.G. Kishalmi - thanks for explanation )
On Mon, Nov 14, 2011 at 1:55 AM, M.G. Kishalmi l...@kishalmi.net wrote:
Eugene,
the link Morten pointed you
to
http://wiki.blender.org/index.php/Dev:Shading/Tangent_Space_Normal_Maps
explains
that
the tangent space you created your normal maps in (in blender)
is generated by the implementation in
mikktspace.h
https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.h
and
mikktspace.c
https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.c
.
you might want to use those in your app (check the licence inside).
cheers,
lmg
On Sun, Nov 13, 2011 at 10:51 PM, Eugene Minov minov@gmail.com
wrote:
Wow!! Thanks a lot, for pointing me to the google ;)
But I afraid that maybe I've not correctly describe my problem. If so,
sorry for that, because my english is still kinda weak.
My problem not in generating a normal maps (a textures) in blender. Not
at
all.
My problem is that I cannot fully correct render my already generated
normal maps in my app. Because, how I mentioned in the last mail, the
usual
methods for this purpose (by UV coords) is not gives me desired results.
So I wanted to ask for help with information about methods blender uses
for
generating tangents.
And yes, I had searched in google but unfortunately have't found
something
helpful yet.
If someone can point me to that kind of info, I will be very grateful!
On Mon, Nov 14, 2011 at 12:08 AM, Morten Mikkelsen
mikkels...@gmail.com
wrote:
There you go buddy -- http://lmgtfy.com/?q=blender+tangent+space
On Sun, Nov 13, 2011 at 8:46 AM, Eugene Minov minov@gmail.com
wrote:
Hi.
I am sorry if I subscribe into a wrong place, I am new and I've not
actually planned to change or to debug the blender sources yet.
But I trying to write app that'll be render models with normal
mapping
exported from blender, and I have a question about how exactly is
blender
calculates a tangent vectors when Unwrap operation in the editing
mode
performs?
Calculating tangents in my app in usual manner (using UV coords and
verts
positions) gives me different tangents for each face of the same
vertex
indexed from, and thus crumpled normal map looking.
Then by looking into blender sources (searching by 'tangent'
keyword)
I've
found a couple of functions with tangents calculations, like:
float axis[3] = {0.0f, 0.0f, 1.0f};
cross_v3_v3v3(tangent, normal, up);
normalize_v3(tangent);
After I tried same method in my program I've gotten almost perfect
looking
model, depending on what initial axis I've used.
To choose, which axis to use (0, 0, 1), (0, 1, 0) or (1, 0, 0) for
each
normal, I calculate max dot product of tangent calculated by each
axis
with
tangent calculated from UV coords.
But still it seems that in some rare vertices tangent is calculates
wrong,
maybe because of wrong initial axis.
So, can anyone please give me any information about tangents
calculation
formula that blender uses while generates UV coords or some advice
about
choosing initial axis.
Thanks for help.
Eugene
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Re: [Bf-committers] Blender tangent space calculation
In the last days I've been doing a blender-ogre material converter
and after learning how each engine calculates the normals from tangent
normal maps, I've found that Ogre::Mesh::buildTangentVectors builds
the necessary vectors compatible with blender ones. It has a couple of
options for splitting mirrored UVs and saving the polarity in the 4th
component, just like blender's generated GLSL code expects.
2011/11/14 Eugene Minov minov@gmail.com:
Hi!
One more question, if I may.
I've seen that there is a couple of the exporter programs which can
generate tangents to export for specific 3D engines only, like OgreExporter.
So why not to simply adding possibility for generate/access a tangent
normals into the python api?
I am not saying that it very hard to generate those tangents using Morten's
implementation directly in program, but think it'll be more a.. consistence
and ease way for people who building their games to properly export their
meshes :)
Maybe if nobody wants, then I'd like to try implement this by some time.
What you guys think about this?
Eugene
On Mon, Nov 14, 2011 at 2:41 AM, Eugene Minov minov@gmail.com wrote:
Oh, my bad :) I've seen that page but I'd thought this page is explains
different baking modes in blender's render.
Morten Mikkelsen - thank you for your great implementation! I'will learn
it!
M.G. Kishalmi - thanks for explanation )
On Mon, Nov 14, 2011 at 1:55 AM, M.G. Kishalmi l...@kishalmi.net wrote:
Eugene,
the link Morten pointed you
to
http://wiki.blender.org/index.php/Dev:Shading/Tangent_Space_Normal_Maps
explains
that
the tangent space you created your normal maps in (in blender)
is generated by the implementation in
mikktspace.h
https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.h
and
mikktspace.c
https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.c
.
you might want to use those in your app (check the licence inside).
cheers,
lmg
On Sun, Nov 13, 2011 at 10:51 PM, Eugene Minov minov@gmail.com
wrote:
Wow!! Thanks a lot, for pointing me to the google ;)
But I afraid that maybe I've not correctly describe my problem. If so,
sorry for that, because my english is still kinda weak.
My problem not in generating a normal maps (a textures) in blender. Not
at
all.
My problem is that I cannot fully correct render my already generated
normal maps in my app. Because, how I mentioned in the last mail, the
usual
methods for this purpose (by UV coords) is not gives me desired results.
So I wanted to ask for help with information about methods blender uses
for
generating tangents.
And yes, I had searched in google but unfortunately have't found
something
helpful yet.
If someone can point me to that kind of info, I will be very grateful!
On Mon, Nov 14, 2011 at 12:08 AM, Morten Mikkelsen
mikkels...@gmail.com
wrote:
There you go buddy -- http://lmgtfy.com/?q=blender+tangent+space
On Sun, Nov 13, 2011 at 8:46 AM, Eugene Minov minov@gmail.com
wrote:
Hi.
I am sorry if I subscribe into a wrong place, I am new and I've not
actually planned to change or to debug the blender sources yet.
But I trying to write app that'll be render models with normal
mapping
exported from blender, and I have a question about how exactly is
blender
calculates a tangent vectors when Unwrap operation in the editing
mode
performs?
Calculating tangents in my app in usual manner (using UV coords and
verts
positions) gives me different tangents for each face of the same
vertex
indexed from, and thus crumpled normal map looking.
Then by looking into blender sources (searching by 'tangent'
keyword)
I've
found a couple of functions with tangents calculations, like:
float axis[3] = {0.0f, 0.0f, 1.0f};
cross_v3_v3v3(tangent, normal, up);
normalize_v3(tangent);
After I tried same method in my program I've gotten almost perfect
looking
model, depending on what initial axis I've used.
To choose, which axis to use (0, 0, 1), (0, 1, 0) or (1, 0, 0) for
each
normal, I calculate max dot product of tangent calculated by each
axis
with
tangent calculated from UV coords.
But still it seems that in some rare vertices tangent is calculates
wrong,
maybe because of wrong initial axis.
So, can anyone please give me any information about tangents
calculation
formula that blender uses while generates UV coords or some advice
about
choosing initial axis.
Thanks for help.
Eugene
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Re: [Bf-committers] Blender tangent space calculation
So why not to simply adding possibility for generate/access a tangent normals into the python api? If it's not already available in the python API then I agree that it's a good idea. However, you'd need to supply support for normals as well since at this point the python API only gives access to the unconditionally averaged/smooth normals at the vertices. Ie. the api doesn't take faces set to soft/hard into account when submitting normals back to the script. ___ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers
Re: [Bf-committers] Blender tangent space calculation
There you go buddy -- http://lmgtfy.com/?q=blender+tangent+space
On Sun, Nov 13, 2011 at 8:46 AM, Eugene Minov minov@gmail.com wrote:
Hi.
I am sorry if I subscribe into a wrong place, I am new and I've not
actually planned to change or to debug the blender sources yet.
But I trying to write app that'll be render models with normal mapping
exported from blender, and I have a question about how exactly is blender
calculates a tangent vectors when Unwrap operation in the editing mode
performs?
Calculating tangents in my app in usual manner (using UV coords and verts
positions) gives me different tangents for each face of the same vertex
indexed from, and thus crumpled normal map looking.
Then by looking into blender sources (searching by 'tangent' keyword) I've
found a couple of functions with tangents calculations, like:
float axis[3] = {0.0f, 0.0f, 1.0f};
cross_v3_v3v3(tangent, normal, up);
normalize_v3(tangent);
After I tried same method in my program I've gotten almost perfect looking
model, depending on what initial axis I've used.
To choose, which axis to use (0, 0, 1), (0, 1, 0) or (1, 0, 0) for each
normal, I calculate max dot product of tangent calculated by each axis with
tangent calculated from UV coords.
But still it seems that in some rare vertices tangent is calculates wrong,
maybe because of wrong initial axis.
So, can anyone please give me any information about tangents calculation
formula that blender uses while generates UV coords or some advice about
choosing initial axis.
Thanks for help.
Eugene
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Re: [Bf-committers] Blender tangent space calculation
Wow!! Thanks a lot, for pointing me to the google ;)
But I afraid that maybe I've not correctly describe my problem. If so,
sorry for that, because my english is still kinda weak.
My problem not in generating a normal maps (a textures) in blender. Not at
all.
My problem is that I cannot fully correct render my already generated
normal maps in my app. Because, how I mentioned in the last mail, the usual
methods for this purpose (by UV coords) is not gives me desired results.
So I wanted to ask for help with information about methods blender uses for
generating tangents.
And yes, I had searched in google but unfortunately have't found something
helpful yet.
If someone can point me to that kind of info, I will be very grateful!
On Mon, Nov 14, 2011 at 12:08 AM, Morten Mikkelsen mikkels...@gmail.comwrote:
There you go buddy -- http://lmgtfy.com/?q=blender+tangent+space
On Sun, Nov 13, 2011 at 8:46 AM, Eugene Minov minov@gmail.com wrote:
Hi.
I am sorry if I subscribe into a wrong place, I am new and I've not
actually planned to change or to debug the blender sources yet.
But I trying to write app that'll be render models with normal mapping
exported from blender, and I have a question about how exactly is blender
calculates a tangent vectors when Unwrap operation in the editing mode
performs?
Calculating tangents in my app in usual manner (using UV coords and verts
positions) gives me different tangents for each face of the same vertex
indexed from, and thus crumpled normal map looking.
Then by looking into blender sources (searching by 'tangent' keyword)
I've
found a couple of functions with tangents calculations, like:
float axis[3] = {0.0f, 0.0f, 1.0f};
cross_v3_v3v3(tangent, normal, up);
normalize_v3(tangent);
After I tried same method in my program I've gotten almost perfect
looking
model, depending on what initial axis I've used.
To choose, which axis to use (0, 0, 1), (0, 1, 0) or (1, 0, 0) for each
normal, I calculate max dot product of tangent calculated by each axis
with
tangent calculated from UV coords.
But still it seems that in some rare vertices tangent is calculates
wrong,
maybe because of wrong initial axis.
So, can anyone please give me any information about tangents calculation
formula that blender uses while generates UV coords or some advice about
choosing initial axis.
Thanks for help.
Eugene
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Re: [Bf-committers] Blender tangent space calculation
Eugene,
the link Morten pointed you
tohttp://wiki.blender.org/index.php/Dev:Shading/Tangent_Space_Normal_Mapsexplains
that
the tangent space you created your normal maps in (in blender)
is generated by the implementation in
mikktspace.hhttps://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.hand
mikktspace.chttps://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.c
.
you might want to use those in your app (check the licence inside).
cheers,
lmg
On Sun, Nov 13, 2011 at 10:51 PM, Eugene Minov minov@gmail.com wrote:
Wow!! Thanks a lot, for pointing me to the google ;)
But I afraid that maybe I've not correctly describe my problem. If so,
sorry for that, because my english is still kinda weak.
My problem not in generating a normal maps (a textures) in blender. Not at
all.
My problem is that I cannot fully correct render my already generated
normal maps in my app. Because, how I mentioned in the last mail, the usual
methods for this purpose (by UV coords) is not gives me desired results.
So I wanted to ask for help with information about methods blender uses for
generating tangents.
And yes, I had searched in google but unfortunately have't found something
helpful yet.
If someone can point me to that kind of info, I will be very grateful!
On Mon, Nov 14, 2011 at 12:08 AM, Morten Mikkelsen mikkels...@gmail.com
wrote:
There you go buddy -- http://lmgtfy.com/?q=blender+tangent+space
On Sun, Nov 13, 2011 at 8:46 AM, Eugene Minov minov@gmail.com
wrote:
Hi.
I am sorry if I subscribe into a wrong place, I am new and I've not
actually planned to change or to debug the blender sources yet.
But I trying to write app that'll be render models with normal mapping
exported from blender, and I have a question about how exactly is
blender
calculates a tangent vectors when Unwrap operation in the editing mode
performs?
Calculating tangents in my app in usual manner (using UV coords and
verts
positions) gives me different tangents for each face of the same vertex
indexed from, and thus crumpled normal map looking.
Then by looking into blender sources (searching by 'tangent' keyword)
I've
found a couple of functions with tangents calculations, like:
float axis[3] = {0.0f, 0.0f, 1.0f};
cross_v3_v3v3(tangent, normal, up);
normalize_v3(tangent);
After I tried same method in my program I've gotten almost perfect
looking
model, depending on what initial axis I've used.
To choose, which axis to use (0, 0, 1), (0, 1, 0) or (1, 0, 0) for each
normal, I calculate max dot product of tangent calculated by each axis
with
tangent calculated from UV coords.
But still it seems that in some rare vertices tangent is calculates
wrong,
maybe because of wrong initial axis.
So, can anyone please give me any information about tangents
calculation
formula that blender uses while generates UV coords or some advice
about
choosing initial axis.
Thanks for help.
Eugene
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Re: [Bf-committers] Blender tangent space calculation
Oh, my bad :) I've seen that page but I'd thought this page is explains
different baking modes in blender's render.
Morten Mikkelsen - thank you for your great implementation! I'will learn it!
M.G. Kishalmi - thanks for explanation )
On Mon, Nov 14, 2011 at 1:55 AM, M.G. Kishalmi l...@kishalmi.net wrote:
Eugene,
the link Morten pointed you
tohttp://wiki.blender.org/index.php/Dev:Shading/Tangent_Space_Normal_Maps
explains
that
the tangent space you created your normal maps in (in blender)
is generated by the implementation in
mikktspace.h
https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.h
and
mikktspace.c
https://svn.blender.org/svnroot/bf-blender/trunk/blender/intern/mikktspace/mikktspace.c
.
you might want to use those in your app (check the licence inside).
cheers,
lmg
On Sun, Nov 13, 2011 at 10:51 PM, Eugene Minov minov@gmail.com
wrote:
Wow!! Thanks a lot, for pointing me to the google ;)
But I afraid that maybe I've not correctly describe my problem. If so,
sorry for that, because my english is still kinda weak.
My problem not in generating a normal maps (a textures) in blender. Not
at
all.
My problem is that I cannot fully correct render my already generated
normal maps in my app. Because, how I mentioned in the last mail, the
usual
methods for this purpose (by UV coords) is not gives me desired results.
So I wanted to ask for help with information about methods blender uses
for
generating tangents.
And yes, I had searched in google but unfortunately have't found
something
helpful yet.
If someone can point me to that kind of info, I will be very grateful!
On Mon, Nov 14, 2011 at 12:08 AM, Morten Mikkelsen mikkels...@gmail.com
wrote:
There you go buddy -- http://lmgtfy.com/?q=blender+tangent+space
On Sun, Nov 13, 2011 at 8:46 AM, Eugene Minov minov@gmail.com
wrote:
Hi.
I am sorry if I subscribe into a wrong place, I am new and I've not
actually planned to change or to debug the blender sources yet.
But I trying to write app that'll be render models with normal
mapping
exported from blender, and I have a question about how exactly is
blender
calculates a tangent vectors when Unwrap operation in the editing
mode
performs?
Calculating tangents in my app in usual manner (using UV coords and
verts
positions) gives me different tangents for each face of the same
vertex
indexed from, and thus crumpled normal map looking.
Then by looking into blender sources (searching by 'tangent'
keyword)
I've
found a couple of functions with tangents calculations, like:
float axis[3] = {0.0f, 0.0f, 1.0f};
cross_v3_v3v3(tangent, normal, up);
normalize_v3(tangent);
After I tried same method in my program I've gotten almost perfect
looking
model, depending on what initial axis I've used.
To choose, which axis to use (0, 0, 1), (0, 1, 0) or (1, 0, 0) for
each
normal, I calculate max dot product of tangent calculated by each
axis
with
tangent calculated from UV coords.
But still it seems that in some rare vertices tangent is calculates
wrong,
maybe because of wrong initial axis.
So, can anyone please give me any information about tangents
calculation
formula that blender uses while generates UV coords or some advice
about
choosing initial axis.
Thanks for help.
Eugene
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