HI CORONA guyz... as a corona user over 2 years, i couldn't find out why we should have Corona mtl and this one (PBR) simultaneously with same behavior!? 🤔 instead of parallel parts i supposed that we see some dramatic improvements in VFX, caustics and speed of rendering for animating ANY WAY... infinite loop⁉ after Chaos group😐 plz be U r self_ forward thinking nothing more!
Not sure what you mean, can you explain more? This material is not the same as the Legacy, e.g. the big obvious examples are that this one has Clear Coat and Sheen, but there are other differences under the hood too that makes this easier to use, less likely to create "fake" materials, and more compatible with other approaches to materials to make importing things from Quixel, Megascans, Substance etc. easier. All of those are the reasons why the material is changing.
As a note, the Physical Material is the new default and recommended to use - the old one is left in place simply for legacy scenes that use it, so you can continue to get identical results from your previous scenes (so that's why you end up with both materials, rather than just the new one).
The merger with Chaos Group has nothing to do with deciding it was time for a new material with more functionality and better compatibility, still entirely our own decision :)