Class: PMREMGenerator

THREE.PMREMGenerator()

new PMREMGenerator()

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. Unlike a traditional mipmap chain, it only goes down to the LOD_MIN level (above), and then creates extra even more filtered 'mips' at the same LOD_MIN resolution, associated with higher roughness levels. In this way we maintain resolution to smoothly interpolate diffuse lighting while limiting sampling computation.
Source:
See: