lodMin top-level property
This class generates a Prefiltered, Mipmapped Radiance Environment Map (PMREM) from a cubeMap environment texture. This allows different levels of blur to be quickly accessed based on material roughness. It is packed into a special CubeUV format that allows us to perform custom interpolation so that we can support nonlinear formats such as RGBE. Unlike a traditional mipmap chain, it only goes down to the lodMin level (above), and then creates extra even more filtered 'mips' at the same lodMin resolution, associated with higher roughness levels. In this way we maintain resolution to smoothly interpolate diffuse lighting while limiting sampling computation.
Implementation
int lodMin = 4;