Which statement correctly compares Ray-Traced shadows to shadow-mapped shadows?

Which statement correctly compares Ray-Traced shadows to shadow-mapped shadows?

• A. Ray-Traced shadows are more accurate than shadow-mapped shadows.
• B. Shadow-mapped shadows are more accurate than Ray-Traced shadows.
• C. They have equal accuracy.
• D. They are not comparable.

Answer: (A)

The main idea is that ray-traced shadows are more accurate because they simulate light interaction directly, per pixel, rather than relying on a precomputed depth map from the light’s viewpoint. With ray tracing, a shadow ray is cast from each point to the light to see if occluders block the light, which naturally captures exact shadow boundaries, soft edges from extended or area lights, and proper self-shadowing and transparency effects. Shadow mapping, by contrast, stores a depth map from the light and compares it during rendering, which can introduce aliasing, shadow bias, and artifacts like shadow acne or bleeding if not carefully tuned. While shadow maps are fast and suitable for real-time workflows, they inherently trade some accuracy for performance. Therefore, ray-traced shadows offer more accurate and physically plausible shadows, especially for softness and complex occluders, at the cost of higher computational load.

The main idea is that ray-traced shadows are more accurate because they simulate light interaction directly, per pixel, rather than relying on a precomputed depth map from the light’s viewpoint. With ray tracing, a shadow ray is cast from each point to the light to see if occluders block the light, which naturally captures exact shadow boundaries, soft edges from extended or area lights, and proper self-shadowing and transparency effects. Shadow mapping, by contrast, stores a depth map from the light and compares it during rendering, which can introduce aliasing, shadow bias, and artifacts like shadow acne or bleeding if not carefully tuned. While shadow maps are fast and suitable for real-time workflows, they inherently trade some accuracy for performance. Therefore, ray-traced shadows offer more accurate and physically plausible shadows, especially for softness and complex occluders, at the cost of higher computational load.