What is the formula of BJS PCSS?

In traditional PCSS,i don’t find the concept of transition speed.
What’s the meaning of contactHardeningLightSizeUVRatio.
I review the core code.It says that:

If we do not use the light radius?And we use contactHardeningLightSizeUVRatio to mock the light radius.

Hello! You can see how the PCSS is implemented here: Babylon.js/shadowsFragmentFunctions.fx at 149a514dd6b1010068ed0c0ca9735b7d74e97ef7 · BabylonJS/Babylon.js · GitHub

lightSizeUVRatio influences the lightSizeUV argument passed to this function.


We use the light radius to simulate soft area lights.And why we do not use the light radius in PCSS?
I don’t quite understand what the second parameter does in texture2D.

The second parameter are the uv coordinates :slight_smile: texture - OpenGL 4 Reference Pages (khronos.org)