What does the Size parameter control in shadow mapping?

What does the Size parameter control in shadow mapping?

• A. Shadow bias
• B. Density
• C. Size
• D. Sample range

Answer: (C)

Size in shadow mapping determines how large the area of the scene is that gets captured into the light’s depth map. The shadow map is a depth texture created from the light’s point of view, and the size defines the width/height of the light’s projection (for a directional light this is the orthographic window; for a spot light it’s the cone footprint). A larger size covers more of the world in the shadow map, but with the same pixel resolution, meaning less texel density per unit area and potentially blurrier shadows or more aliasing far from the camera. A smaller size concentrates detail in a smaller region, giving crisper shadows there but reducing coverage and causing shadows to disappear for objects outside the mapped area.

Size in shadow mapping determines how large the area of the scene is that gets captured into the light’s depth map. The shadow map is a depth texture created from the light’s point of view, and the size defines the width/height of the light’s projection (for a directional light this is the orthographic window; for a spot light it’s the cone footprint). A larger size covers more of the world in the shadow map, but with the same pixel resolution, meaning less texel density per unit area and potentially blurrier shadows or more aliasing far from the camera. A smaller size concentrates detail in a smaller region, giving crisper shadows there but reducing coverage and causing shadows to disappear for objects outside the mapped area.