2 months ago
- Transition period: Ray tracing and rasterization coexist in real-time rendering.
- Rasterization often handles primary visibility, while ray tracing adds shadows, reflections, or global illumination.
- Goal: Compute camera rays consistent with rasterization, using world to clip space (view-projection) matrix.
- Clip space uses homogeneous coordinates to simplify perspective projection and division.
- Camera rays defined by origin and direction; origin computed from near clipping plane in world space.
- Bad approach: Compute ray direction via far and near plane points; prone to numerical cancellation.
- Good approach: Use intersection of planes in clip space to compute ray direction robustly.
- Faster solution: Precompute cross products for optimized ray direction calculation.
- Ray parameter at far plane derived via intersection with far clipping plane in homogeneous coordinates.
- Code provided for GLSL and HLSL; integration into renderers discussed with standardization benefits.