Distance field shadows

This recipe is quite short, but too sweet to be just a quick tip. Besides what was discussed in the previous recipe, there is a further pre-computed shadow type that is off by default. The full name for it is a signed distance field baked shadow. But what does that mean? UDK has this method built into its dominant lights, and once enabled it replaces the native shadows. Besides being distance based, a key difference is in the compactness of the information stored. The technology is derived from Valve's Alpha Tested Magnification and effectively stores the lighting information in the separate RGB channels of a texture. For more information, explore Valve's paper, which discusses limited texture artifacts: http://www.valvesoftware.com/publications/2007/SIGGRAPH2007_AlphaTestedMagnification.pdf.

Getting ready

Open the provided scene Packt_08_LightEnvironment_DEMO.UDK. This is the same scene as was used previously. Roll the camera over some area of the ground where the trees...