"Rendering Grass in Real Time with Dynamic Lighting" SIGGRAPH 2006
Three LOD levels(LOD は 3 段階)
Medium distance grass: axis-aligned semitransparent slices (中の LOD では軸平行な半透明のスライス)
Bidirectional Texture Functions : 5 light_directions * 2 view directions (ランタイムでは, 5方向のライトと 2 方向の視点のライティング済の結果を参照してブレンド)
Shadows from other blades are approximated by shadow mask mapped onto the cylinder (他の草からの影は円柱に投影したシャドウマップで近似)
Reference
- Bidirectional Texture Functions : "Real-time rendering of realistic-looking grass" 2005
- Geometry and Billboards : "Animating prairies in real-time" I3D 2001
