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Type: Posts; User: Sunray

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    Re: Manual bilinear PCF seams on AMD

    Solved by snapping to integer coordinates. Apparently, you can't trust GL_NEAREST.



    ...
    vec2 Fraction = fract(Dimensions * TexCoord.xy);

    TexCoord.xy -= Fraction / Dimensions; // <--
    ...
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    Manual bilinear PCF seams on AMD

    I did a bilinear filter for shadow maps, which I've also done quite a few times before over the years. But this time around I got some weird seams. Is there someone who has a sensible explanation for...
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    Re: Texture3D deprecated?

    Since texture filtering is a part of the texture state I'm sure you would have to do the filtering yourself.

    I'm pretty sure that GLSL doesn't define any > operator for vec3, so if the NVIDIA...
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    Re: Texture3D deprecated?

    texture(), the actual texture type is already known from the input sampler type.
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    Re: Problems with uniform blocks

    Sweet!
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    Re: Uniform Buffer Objects (slow) - help needed

    This is how I do it, and it works fine on ATI.

    First of all I use strictly UBO since the rendering API must be compatible with DX10/DX11. For all dynamic uniforms (those who are updated every...
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    Re: Many VBOs vs. single VB for dynamic meshes

    I current have huge problems with dynamic VBO:s on Radeon cards. I do a lot of GUI rendering and for this I have a Vertex Buffer Pool from which the rendering code is allocating from. This pool...
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    Re: ARB_FrameBuffer_Object on Radeon 4850

    I believe I asked Humus this once at my previous work. He said it was purely a driver restriction and has nothing to do with the hardware.
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    Re: Deferred Shading Stencil Tests

    Doesn't work on ATI (results in garbage on screen). I've sent them a bug report few months ago.
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    Re: 8.11: GL_EXT_transform_feedback on ATI card!

    Thumbs up for AMD.
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    Re: interpolation function

    mix(a, b, c)
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    Re: ATI Radeon HD 4800 OpenGL features

    I guess they have to if they want support games running id tech 5 (Rage, Doom 4).

    Question: Is it possible to use ATI Fetch4 for shadow maps in OpenGL? I find zero info on the net.
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    Re: Help with eyeZ calculation?

    This should work: gl_ProjectionMatrix[3].z/(Z * -2.0 + 1.0 - gl_ProjectionMatrix[2].z)
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    Re: ATI Radeon HD 4800 OpenGL features

    It seems to work. My graphics engine relies on FBO with stencil and at first it didn't work at all with R4850. Then I added an additional color target to store and sample depth from and made the...
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    Re: ATI Radeon HD 4800 OpenGL features

    I've noticed that you can't sample from a 24 bit depth texture (GL_DEPTH_COMPONENT24, GL_DEPTH24_STENCIL8) on Radeon 4850. All you get is random values. However DEPTH_COMPONENT16/32 works fine.
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    Re: Deferred shading

    Try "zOverW = zOverW * 2.0 - 1.0". This should be the exact same thing as I wrote. However I forgot to divide pos by pos.w. :)
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    Re: Deferred shading

    In normalized device coordinateds (NDC) x,y,z are in the range [-1, 1].

    It should be something like this:



    VertexShader:
    ClipPos = gl_Position;

    FragmentShader:
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    Re: Deferred shading

    A simpler way (IMO) to calculate the view space position is "Position = gl_ProjectionMatrixInverse * Ndc" where Ndc is known from gl_Position.xy/gl_Position.w and the sampled depth value. It's...
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    Re: Stencil pass for deferred lighting

    I guess you want to find all pixels that are intersecting a convex volume? If so, this is the same problem as stencil shadow volumes. Look up z-fail shadow volumes.
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    Re: Deferred shading

    Aren't normal maps RGBA8 already? So how can fetching normals from a RGBA8 texture, rotating them to world space and storing them in a RGBA8 texture, loose precision?

    Maybe I'm missing something...
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    Re: specular lighting looks wrong

    Is that per-vertex specular?
  22. Thread: Shader Model x?

    by Sunray
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    Re: Shader Model x?

    #ifdef should work in GLSL iirc.
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    Re: how to make shadows in 2007

    Cascade shadow maps are probably the easiest and most stable method IMO. Very easy to implement, no bad worst cases, only poor (but not that poor) performance. :)
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    Re: Certain ATI chips and GLSL

    Have you read the compile and link info logs?
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    Re: suppress self shadows

    The popping that occurs comes from phong (or gouraud if someone uses that :) ) shading, since it also illuminate backfaces. There are a few ways to deal with it.

    1) N.L^value, to "narrow" the...
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