“With EXR1, to access one layer or channel, you had to load the entire file in. With EXR2, you can load just and only what you need, speeding up production.”
Unfortunately at this time default 3dsmax Vray will not output a correctly optimized Multi element EXR (external programs i.e NUKE allowing only loading of elements that are requested. This saves on load/read time).
Vray 3.3 has added a option in the render elements called VRayOptionRE.
- Unfiltered fragment mode : (untested) Best coverage
- EXR Compresion : ZIPS
- EXR Multipart : On
If your having issue with V-Ray not saving a correct EXR 2.2 (for use in Nuke) Add in a VRayOptionRE render element. Then enable exr multipart
The official help file has nothing on it but it did help us at Teague.