from geometry to pixels

Fragment Shader

Ray-Tracing Hardware

Ray-Tracing vs. Rasterization The question which of these techniques is “better” is nearly as old as the field of computer graphics itself. As ray-tracing simulates light transport it is simple to get realistic images using this technique. This is why it is often used when realism is the top priority, e.g. in rendering movies. Rasterization […]


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OpenGL Programmable Blending – APPLE_shader_framebuffer_fetch

Large parts of the rendering pipeline are user programmable through shaders nowadays. One of the remaining fixed-functions is fragment blending: The new fragments (shaded by the fragment shader) don’t neccessarily have to overwrite the corresponding framebuffer entry, we can set different blending operations. The set of possible operations however is fixed. There have been requests […]


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Photoshop Blendmodi in GLSL

I once wrote a texturing tool in which you could paint on a 3D model on multiple layers. These layers were composing the final texture just as you know it from photoshop, complete with alpha, opacity slider and: blend modes. these blend modes are quite simple to implement and it can be useful to use […]


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GPU Rasterizer Pattern

Visualizing the pattern in which the fragment processors are called for the individual fragments are some kind of ‘Hello World’ for atomic counters. The order in which the fragments generated by a draw call are created and the fragment shaders are calles are not defined, so the hardware can choose each order that best matches […]


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