I'm doing research to implement a shadow algorithm for omnidirectional soft shadows in a real-time 3D renderer. I've read about PCF but to me it doesn't look very realistic since it doesn't "fade" with the distance to the blocker like PCSS would.
The problem is PCSS uses the penumbra radius to simulate the "fade" effect which omnidirectional lights don't create. Therefore, only lights that do produce a penumbra (like area lights) are natively supported by the algorithm.
So I'll break this question into 2:
- Can I still use PCSS on omnidirectional lights by "cheating" and applying a tweaked constant value as the light area parameter?
- Is there another algorithm that produces this "fade" effect and does work with omnidirectional lights?