QRAD

Quake Radiosity, often just shorted to QRAD, was one of the sets of tools originally shipped with the Half-Life mod tools that compiled radiosity and lightmap data into a map.

This was one of the most bugged tools out of the original sets of tools. ZHLT found that this tool packed the direct lighting data into a map twice resulting in longer compile times. He also found that every PVS required a light_environment for lighting an outdoor area, which could be tedious for mappers.