[osg-users] multipass calculating with shaders
Hi, first I would like to reask the question I sent few days ago since it might have been overlooked so here it is: Hello, in the osg examples there are several examples of how to use RTT. I would like to concatenate several renderings. I mean, render the scene to texture1, then use texture1 to create texture2, then use texture1 texture2 to create texture3 and so on. I don't understand how to control the order of the rendering. I tried to change the rendering order number of the camera's I used in PRE_RENDER and it didn't seem to have any effect. The results seems fine, but I don't know if it used the data in the texture from the current frame or the previous. (in the example I made to check this ability, I render the cow to texture, then using PRE_REND ER shader I remove the red plane and later I remove the green plane, changing the order should result in different images) this brings me to the next question. I tried to clear the texture used to render the Scene to. I tried setting the texture image to new allocated image, dirty the texture parameters and dirty the texture object and nothing seems to have the required result. dirty the texture object results as blank screen, the other operation doesn't seem to clear the texture since changing the order in the multipass didn't change the results. another problem I had was to render in different passes to the same texture. (Even if it was in the POST_RENDER sub tree). is there a way to reuse the same texture in different passes? the last problem I encountered is that I rendered the resulting textures, using several cameras NESTED_RENDER each drawing a square with different texture attached 2 it and each camera has different viewport. The problem is the is the cameras viewport intersected, I couldn't change the order they are rendered (to make one of them on top of the other). I tried setting the RenderDetaill with higher and lower numbers, both for the Camera and for the Geodes, with no success. any ideas concerning any of the problems would be appriciated. thanks, Guy. second, I want to render single or several (4 - 8) values which represnt some calculation. So I use render to texture. The texture is 1D and to render to it I use orthographic projection, and the viewport fits to the texture dimension. The geometry I render is points. One point per calculation, and each point should result as one pixel. Is this the right way? I has to set the point size to 1.5 to see anything, any ideas why? thanks, Guy. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] multipass calculating with shaders
thanks, I'll try that. more problems I'm facing is setting the image internal data type, I've seen in the examples setting the internal type to 3 or 4. what does it mean? how do I set it to float or int? and I couldn't read from the image even that I used code very similar to osgprerender example :(, the image-data() return buffer filled with garbage. but thanks anyway, Guy. - Original Message - From: John Donovan [EMAIL PROTECTED] To: OpenSceneGraph Users osg-users@lists.openscenegraph.org Sent: Monday, September 17, 2007 3:43 PM Subject: Re: [osg-users] multipass calculating with shaders [EMAIL PROTECTED] wrote: second, I want to render single or several (4 - 8) values which represnt some calculation. So I use render to texture. The texture is 1D and to render to it I use orthographic projection, and the viewport fits to the texture dimension. The geometry I render is points. One point per calculation, and each point should result as one pixel. Is this the right way? I has to set the point size to 1.5 to see anything, any ideas why? It sounds like you need to offset your point centres by 0.5 I don't have the spec in front of me, but I think you've got to shift it in the positive direction on both axes, but you may have to play with the signs until it works :) -J __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] multipass calculating with shaders
[EMAIL PROTECTED] wrote: thanks, I'll try that. more problems I'm facing is setting the image internal data type, I've seen in the examples setting the internal type to 3 or 4. what does it mean? how do I set it to float or int? I use the following code for rendering to a floating-point texture: _texture = new Texture2D; _texture-setResizeNonPowerOfTwoHint(false); _texture-setTextureSize(_totalWidth, _totalHeight); _texture-setSourceType(GL_FLOAT); _texture-setSourceFormat(GL_RGB); _texture-setInternalFormat(GL_RGB32F_ARB); _texture-setFilter(Texture2D::MIN_FILTER, Texture2D::NEAREST); _texture-setFilter(Texture2D::MAG_FILTER, Texture2D::NEAREST); and I couldn't read from the image even that I used code very similar to osgprerender example :(, the image-data() return buffer filled with garbage. If I understand it correctly, the Image associated with a Texture is used for uploading the data into the texture. If you want to read from the texture, you'll need to copy it to a buffer. I can't remember how to do that off-hand, but it'll likely be fairly slow. -J __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] multipass calculating with shaders
thank Jhon. I want to read the buffer from the texture only for debug purposes. In the final program I won't do it. I need to associate image with the texture to set it's initial values, and later some passes in the multipass sequences are updating this data. The problem is that after associating image with the texture, I think the image reads automatically the texture buffer (take the osgprerender example for instance, there is an image and in the post render they play with it's buffer, which means the image read the current texture), and this might slow down the program. Another thing is as I mentioned earlier: I need to set the initial values of the texture, and the only way I know how to do it is using images, so the question is how do I set images internal type, pixel type and gltype, to be float, long, etc... (unsigned char appears in the examples). btw, I offset the point by half and it worked for one pass that renders about 3 pixels. it didn't work for other pass that renders 1 pixel. is there a problem when the viewport is 1x1? thanks a lot, Guy. - Original Message - From: John Donovan [EMAIL PROTECTED] To: OpenSceneGraph Users osg-users@lists.openscenegraph.org Sent: Monday, September 17, 2007 4:54 PM Subject: Re: [osg-users] multipass calculating with shaders [EMAIL PROTECTED] wrote: thanks, I'll try that. more problems I'm facing is setting the image internal data type, I've seen in the examples setting the internal type to 3 or 4. what does it mean? how do I set it to float or int? I use the following code for rendering to a floating-point texture: _texture = new Texture2D; _texture-setResizeNonPowerOfTwoHint(false); _texture-setTextureSize(_totalWidth, _totalHeight); _texture-setSourceType(GL_FLOAT); _texture-setSourceFormat(GL_RGB); _texture-setInternalFormat(GL_RGB32F_ARB); _texture-setFilter(Texture2D::MIN_FILTER, Texture2D::NEAREST); _texture-setFilter(Texture2D::MAG_FILTER, Texture2D::NEAREST); and I couldn't read from the image even that I used code very similar to osgprerender example :(, the image-data() return buffer filled with garbage. If I understand it correctly, the Image associated with a Texture is used for uploading the data into the texture. If you want to read from the texture, you'll need to copy it to a buffer. I can't remember how to do that off-hand, but it'll likely be fairly slow. -J __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
