soubok - Developer IT

Record an OpenGL animation

- by Soubok

I need to record an avi from an OpenGL window (not fullscreen). Do you know a free software for windows XP that can help me ?

How to debug a GLSL shader ?

- by Soubok

I need to debug a GLSL program but I don't know how to output intermediate result. Is it possible to make some debug traces (like with printf) with GLSL ?

Shadow volume shader optimization (GLSL)

I wondering if there is a way to optimize this vertex shader. This vertex shader projects (in the light direction) a vertex to the far plane if it is in the shadow. void main(void) { vec3 lightDir = (gl_ModelViewMatrix * gl_Vertex - gl_LightSource[0].position).xyz; // if the vertex is lit if ( dot(lightDir, gl_NormalMatrix * gl_Normal) < 0.01 ) { // don't move it gl_Position = ftransform(); } else { // move it far, is the light direction vec4 fin = gl_ProjectionMatrix * ( gl_ModelViewMatrix * gl_Vertex + vec4(normalize(lightDir) * 100000.0, 0.0) ); if ( fin.z > fin.w ) // if fin is behind the far plane fin.z = fin.w; // move to the far plane (needed for z-fail algo.) gl_Position = fin; } }

Read the article

change the color of a vertex in a vertex shader

- by Soubok

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 ?

Read the article

set the color of a vertex using a GLSL vertex shader

- by Soubok

Is it possible to set the color of a single vertex (not a face) using a GLSL vertex shader program (using GL_ARB_shading_language_100 extension) ?

Read the article

cheapest way to draw a fullscreen quad

- by Soubok

I wondering if there is a faster way to draw a full-screen quad in OpenGL: NewList(); PushMatrix(); LoadIdentity(); MatrixMode(PROJECTION); PushMatrix(); LoadIdentity(); Begin(QUADS); Vertex(-1,-1,0); Vertex(1,-1,0); Vertex(1,1,0); Vertex(-1,1,0); End(); PopMatrix(); MatrixMode(MODELVIEW); PopMatrix(); EndList();

Read the article

make a 3D spotlight cone matrix

- by Soubok

How to create the transformation matrix (4x4) that transforms a cylinder (of height 1 and diameter 1) into a cone that represents my spotlight (position, direction and cutoff angle) ? --edit-- In other words: how to draw the cone that represents my spotlight by drawing a cylinder through a suitable transformation matrix.

Developer IT