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solinent

OpenGL R32G32 opengl texture format

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solinent    124
I need more precision from a texture format in order to do variance shadow mapping. If I switch my code to use GL_RGBA16, it takes a long time to render a scene, but this could also be because of glsl. How shall I get 16 or 32 bits of precision from my floats, while using GLSL? Right now I'm using GL_RGBA, and changing it to GL_RGBA8 doesn't change the IQ, so it must be using only 8 bits per component. Thanks

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V-man    813
Wouldn't a depth texture be better for doing shadows?
Use a format like GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, GL_DEPTH_COMPONENT32

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solinent    124
I'm using variance shadow mapping, so I require two components (depth, and depth^2).

I found the texture target GL_RGBA16F_ARB, and it works!

But what's the difference between GL_RGBA16, and GL_RGBA16F_ARB? Is it just that the latter is a floating point format?

Also, how well is ARB_texture_float supported? I don't really care that much, but would like to know if you know (I'll check google).

Thanks for the speedy response!

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swiftcoder    18437
Quote:
Original post by V-man
ARB_texture_float seems to be supported on everything.
ARB_texture_float only ensures support for floating-point textures, in particular, it does *not* seem to ensure support for floating point render targets.

I believe you need ARB_color_buffer_float in order to render to floating-point textures, and for example, my Intel X3100 (Mac drivers) is missing support for this.

Quote:
Original post by solinent
It's hard to find a comprehensive OGL reference that includes extensions (online).
The definitive reference: http://www.opengl.org/registry/.

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