mrdoob/three.js — pull request #4332 by gazliddon (2014-01-24 10:31:27+00:00)
Title: Updated WebGlRenderer render Method Documentation

The WebGlRenderer.render's forceClear argument forces a
clear -only- for buffers with their .autoClear property is set to true.

Took me a while to find a bug in my code as I didn't understand
these flags overode the forceClear parameter for WebGlRenderer.render