Re: [Flightgear-devel] opengl texgen - projected textures
Manuel Massing wrote: Hello Harald, I am trying to project a texture on the scenario background. A priori everything is setup correctly and the code should work but at the end I only get a projection on the screen space. picture here : hmm, don't have the time to delve deeper into your example, but you seem to be using the same projection matrix for light and camera, so the outcome is expected... keep in mind that OpenGL will multiply the texgen matrix with the inverse of the camera matrix at time of specification. So you have to make sure that modelview is set to the camera view at that point. If you use the light point of view, the texgen results in an identity transform + projection. If the light projection matrix matches the camera, fragment and texture coordinates will be identical (modulo bias), thus the screen plane alignment of your projection. Also, a possible caveat: depending on the storage layout of SGMatrix, you might need to feed OpenGL the transposed texgen matrix as plane vectors (and use the transposed bias matrix i have seen lying around :-)). bye, Manuel ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d You are right, it is indeed working with another light view matrix. Thx ;) Harald. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] opengl texgen - projected textures
Hello Harald, > I am trying to project a texture on the scenario background. A priori > everything is setup correctly and the code should > work but at the end I only get a projection on the screen space. > picture here : hmm, don't have the time to delve deeper into your example, but you seem to be using the same projection matrix for light and camera, so the outcome is expected... keep in mind that OpenGL will multiply the texgen matrix with the inverse of the camera matrix at time of specification. So you have to make sure that modelview is set to the camera view at that point. If you use the light point of view, the texgen results in an identity transform + projection. If the light projection matrix matches the camera, fragment and texture coordinates will be identical (modulo bias), thus the screen plane alignment of your projection. Also, a possible caveat: depending on the storage layout of SGMatrix, you might need to feed OpenGL the transposed texgen matrix as plane vectors (and use the transposed bias matrix i have seen lying around :-)). bye, Manuel ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
[Flightgear-devel] opengl texgen - projected textures
I am trying to project a texture on the scenario background. A priori everything is setup correctly and the code should work but at the end I only get a projection on the screen space. picture here : http://sites.estvideo.net/tipunch/flightgear/shadow/fgfs-screen-044.jpg It's the leftmost texture from the bottom of the screen that should be projected on the ground. I added a diagonal line to clearly see that there is no perspective on the screen projection. If someone is courageous enought the code is here : http://sites.estvideo.net/tipunch/flightgear/shadow/shadowmap.cxx <= new file http://sites.estvideo.net/tipunch/flightgear/shadow/shadowmap.hxx <= new file http://sites.estvideo.net/tipunch/flightgear/shadow/render.diff <= patch for render.cpp use an external view. Harald. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
