mrdoob/three.js — pull request #2698 by MiiBond (2012-11-28 21:47:03+00:00)
Title: Moved bilinear filtering of shadow maps into the shader.

I moved the bilinear filtering of shadow maps into the fragment shader. Previously, the filtering on the shadowmap was set to THREE.LinearFilter and this won't work properly for shadow filtering. For proper PCF, the filtering needs to be done after the depth comparison. i.e. the filtering is done on the shadow value, not the depth value.

This produces much softer shadows than the current code. It is, however, a bit more expensive, so perhaps this is something that has already been considered and rejected?