031b39521a
This is another extreme old one; from before NaN days even! Issue is that shadowbuffers have a bias to prevent faces shadowing itself. To make bias smarter, code was added to adjust bias based on light angle. This correction allowed a factor of 10 times smaller bias, being in many cases much too strong, causing frontally lighted faces becoming too dark. New correction only halves the bias on frontal light, which looks quite more convincing and pretty.