Cascaded Shadow Mapping Architecture for Large-Scale WebGL Viewports
Eliminating pixelated shadow edges and perspective aliasing in large architectural scenes through frustum splitting and PCF filtering.
Standard shadow maps suffer from severe perspective aliasing when applied across extensive camera distances. Cascaded Shadow Maps (CSM) solve this by partitioning the view frustum into logarithmic slices, rendering targeted shadow textures for each cascade.
1. Logarithmic Frustum Splitting
Distributing shadow map cascades using a hybrid combination of linear and logarithmic distance metrics ensures high shadow depth resolution near the camera while covering distant objects efficiently.
2. Percentage-Closer Filtering (PCF) Soft Shadows
Applying multi-sample PCF kernel filtering in fragment shaders softens shadow map boundaries, hiding Texel discretization artifacts without heavy blur passes.
3. Cascade Blend Transitions
Implementing linear blending between adjacent shadow cascade boundaries prevents visible seam artifacts as the main camera orbits through large CAD models.