Particles with motion blur alpha issue

V-Ray V-Ray for 3ds Max Issues
1

I’ve attached 2 images. First is render direct from vray, second is imported EXR (32 bit float with alpha). I lose a lot of detail in the image for some reason. Any way to resolve this ?

VRAY.jpg
VRAY.jpg1904×1076 169 KB

AFTEREFFECTS.jpg
AFTEREFFECTS.jpg1910×1073 77.9 KB

2

umh, it looks like double premultiplication.
Or, you have some CC in the VFB, absent in AE.
An EXR would be most welcome, though. :slight_smile:

3

Here you go. I have just output as a exr with alpha on a black background. I then imported into AE which defaults to premultiplied. Not sure how it would be double premult ?
butters_final_.origRGB.0212.zip (5.82 MB)

4

It seems to work in Nuke, and look similar what you have in AE if i premult it (see attached).

load.jpg
load.jpg2595×1568 247 KB
premult.jpg
premult.jpg2595×1568 211 KB

5

Hmm. So I only have the option to premult or straight the alpha. straight doesn’t work. Premult just gives the result that isn’t correct. Do I need to add an effect or something ?

6

“unpremult”?
Which is lingo for “divide” by the alpha. :slight_smile:

7

Brilliant. That works well. Thanks :slight_smile: