Graphics Processing CS418 Computer Graphics John C. Hart Graphics - PowerPoint PPT Presentation

Graphics Processing CS418 Computer Graphics John C. Hart

Graphics Processing Graphics Processor Triangle mesh with Image of RGB-colored vertices at 3-D floating- pixels at 2-D integer point spatial coordinate planar coordinate positions (x,y,z) positions (x,y)

Graphics Processing Graphics Processor Triangle mesh with Image of RGB-colored vertices at 3-D floating- pixels at 2-D integer point spatial coordinate planar coordinate positions (x,y,z) positions (x,y)

Graphics Processing Vertex Fragment Scan Converter Shader Shader Triangle with vertices at 3-D floating-point spatial coordinate positions (x,y,z)

Graphics Processing Vertex Fragment Scan Converter Shader Shader Triangle mesh with vertices at 2-D floating-point viewing window coordinate positions (x,y)

Graphics Processing Vertex Fragment Scan Converter Shader Shader Integer pixel positions (x,y) covered by triangle

Graphics Processing Vertex Fragment Scan Converter Shader Shader Integer pixel positions (x,y) with RGB colors

Graphics Processing Vertex Fragment Scan Converter Shader Shader Lots of vertices processed independently of each other

Graphics Processing Vertex Fragment Scan Converter Shader Shader Lots of vertices Lots of fragments processed (pixels) processed independently of independently of each other each other

Serial Processing • Single processor • Single instruction pointer (IP) indicates which instruction will be executed next • Same program needs to be re-run on each data item vertex data vertex shader IP Proc DP

Multi-Core (CPU) Processing • Multiple processors, each with its own IP • Can work on multiple data items simultaneously vertex data vertex shader IP Proc DP IP Proc DP

SIMD Processing • Single Instruction Multiple Data processing • Array of processors, all sharing the same IP • Each processor operates on its own data pointer vertex data vertex shader IP DP Proc DP Proc Proc DP Proc DP

Many-Core (GPU) Processing • SIMD arrays of 32 processors IP IP (“warp” of threads) DP Proc DP Proc • Arrays of SIMD arrays DP Proc DP Proc • Can process thousands of vertices DP Proc DP Proc or pixels each clock DP Proc DP Proc vertex data vertex shader IP IP DP Proc DP Proc DP Proc DP Proc DP Proc DP Proc DP Proc DP Proc

What Have We Learned Vertex Fragment Scan Converter Shader Shader • Three steps to render a mesh 1. Process the vertices 2. Scan convert into fragments 3. Process the fragments • Write custom parallel programs for vertex shaders and fragment shaders • Shaders run on SIMD array processors