void main(void) { vec4 clipCoord = glModelViewProjectionmatrix * gl_Vertex; gl_Position = clipCoord; gl_FrontColor = gl_Color; vec3 ndc = clipCoord.xyz / clipCoord.w; So the clipCoord is just doing standard fixed pipeline ransforms. Now, the ndc ... why do I divide by w, and what do I get from this? ...
The Orange book, section 16.2, lists implementing diffuse lighting as: void main() { vec3 N = normalize(gl_NormalMatrix * gl_Normal); vec4 V = gl_ModelViewMatrix * gl_vertex; vec3 L = normalize(lightPos - V.xyz); gl_FrontColor = gl_Color * vec4(max(0.0, dot(N, L)); } However, when I run this, the lighting changes when I move m...
Is it possible to set the color of a single vertex using a GLSL vertex shader program, in the same way that gl_Position changes the position of a vertex ? ...
I'm trying to implement an algorithm from a graphics paper and part of the algorithm is rendering spheres of known radius to a buffer. They say that they render the spheres by computing the location and size in a vertex shader and then doing appropriate shading in a fragment shader. Any guesses as to how they actually did this? The po...
Hi all, I'm playing about with some vertex and fragment shaders using Cg on my little netbook (running Linux). Clearly I'm going to frequently hit resource limits for my graphics controller, so was wondering if there's a nice way to run the shaders on the CPU, just to test them. Something like D3D's refrast... TIA Andy ...
In HLSL, is there any way to limit the number of constant registers that the compiler uses? Specifically, if I have something like: float4 foobar[300]; In a vs_2_0 vertex shader, the compiler will merrily generate the effect with more than 256 constant registers. But a 2.0 vertex shader is only guaranteed to have access to 256 consta...
I have a vertex shader (2.0) doing some instancing - each vertex specifies an index into an array. If I have an array like this: float instanceData[100]; The compiler allocates it 100 constant registers. Each constant register is a float4, so it's allocating 4 times as much space as is needed. I need a way to make it allocate just 2...
I do not understand why the following two shaders produce different results when I render a vertex buffer with x coordinates equal to zero: First: attribute vec3 position; void main() { gl_Position = vec4(position.x, position.y, 0.0, 1.0); } Second: attribute vec3 position; void main() { gl_Position = vec4(0.0, position.y, 0.0...
Is it possible to apply a filter to the geometry data that is to be rendered using Compute Shader and then use the result as an input buffer in the Vertex Shader? That would save me the trouble (&time) of reading back the data. Any help is much appreciated. ...