3 replies to this topic

[mgoss]

http://the-witness.net/news/wp-content/gallery/valient-shaderx6-figures/figure_412.png

I saw this image and I currently have CSM implemented in my SlimDx project. However, when the camera roates, you notices the shadows move slightly. I'm not talking about the jagged edges that swim. I was hoping someone could explain more of the process about using bounding spheres for stabling CSM.

Thanks in advance.

[TiagoCosta]

To remove the edge shimmering you can follow this article scroll down to the section "Moving the Light in Texel-Sized Increments" and also this topic (read the second MJP post and you should be able to fix it!).

Edited by TiagoCosta, 21 June 2012 - 09:15 AM.

[MJP]

The image is from ShaderX6, if you're interested. The basic idea is that for each cascade, you partition the viewing frustum using a depth range and then build the 8 corners around the slice of the frustum representing that particular partition. Normally you build a light-space AABB around those corners to get a tight fit, but with stable CSM you use a bounding sphere instead (which you can actually do in world space instead of light space, since it doesn't matter for a sphere). Then you also do a little math to round off the translation of each partition, so that they only move in texel-sized increments.

[mgoss]

Thanks guys! I might check out buying that book.