Real-Time Shaders

1. Real-Time Shaders Pilgrimage 2003 Thant Tessman

2. Talk Outline • Fixed-Function Graphics Pipeline • Vertex and Fragment Program Extensions • Cg/HLSL http://developer.nvidia.com

3. Fixed-Function Graphics Pipeline • Geometry Ultimately Specified as Primitives • Triangles • Lines • Points • Which are in Turn Specified as Vertices • Primitives Rasterized to Fragments

4. Vertex Properties • Position • Normal • Color(s) • Texture Coordinate(s)

5. Vertex Properties • Position • Transformed by MODELVIEW Matrix • Normal • Color(s) • Texture Coordinate(s)

6. Vertex Properties • Position • Normal • Transformed by Inverse Transpose of MODELVIEW Matrix • Optionally Renormalized • Color(s) • Texture Coordinate(s)

7. Vertex Properties • Position • Normal • Color(s) • Specified Directly or • Generated from Transformed Per-Vertex Normals and Current Lights and Material • Texture Coordinate(s)

8. Vertex Properties • Position • Normal • Color(s) • Texture Coordinate(s) • Specified Directly or • Generated from Transformed Vertex and Normal • Transformed by TEXTURE Matrix

9. Resulting Vertex Properties • Homogenous Clip-Space Position (x,y,z,w) • Color(s) • Texture Coordinate(s)

10. Primitive Assembly • Optionally Clipped by User-Specified Planes • Transformed by Projection Matrix • Clipped by Viewing Frustum • Perspective Division by w • Viewport & Depthrange Transformations • Polygons Optionally Culled • Rasterization to Fragments

11. Too Many Extensions

12. Lights, Material, Matrices, etc… Vertex State OpenGL Extensions Program Parameters Vertex Attributes DP3, RSQ, MUL, MAD, MAX, DP4, EXP, etc… Vertex Programs

13. Vertex Program Results • Homogenous Coordinate • Color • Texture Coordinates

14. Vertex Programs OpenGL Extensions are Your Problem Now

15. Fragment Attributes • Window Coordinate • Colors • Texture Coordinates

16. Fragment Program Output • Color • Depth

17. Cg/HLSL Compiles to Vertex/Fragment Programs

18. Real-Time Shaders The New 3D Graphics Programming Paradigm