Does comping channels to get beauty pass only work on 32bit?

[joconnell]

Yep - it's only the two raw passes and their filters that don't work correctly, and also using multiplication in compositing can lead to issues as per vlado. The passes give you a lot and you're probably never going to be so drastically off target that you'd need the raw passes anyway - if you ware tweak your 3d settings first!

[Morne]

There is no documentation for half of the features that spells things out that any normal person can understand, we have to rely on help from the forums. Thankfully some of the veterans here on this forum gives their time and effort to help. Just sometimes there are so many users and so many threads that it's difficult to distinguish CORRECT information from not so correct information. The forum is pretty much like a Google search, somewhere in there between all the irrelevant search results, lies the answers you're looking for.

Years ago I used Chris Nichols' method for comping. It seemed pretty solid to me (but maybe it wasn't as solid and I just didn't notice problems???).
But I haven't used it in a while and was confused when people suddenly started saying that you can't comp channels to get back to your beauty pass.

...using multiplication in compositing can lead to issues as per vlado.

joconnell please could you point me to this information. I don't recall seeing this before.

[joconnell]

I think it's mainly along edges where you get some problems Morne so for example if you're trying to use the Raw passes and their filters, you need to multiply one by the other. If you avoid using the raw passes and just go with Lighting, GI, spec, reflect, refract then you're only ever using add / plus and it gives you something pretty much spot on - fair enough you get ultimate control by using the raw passes but hopefully your 3d render won't be so far off what you want as a result that you'd actually need all that extra stuff.

[Morne]

It makes more sense now, thanks for the explanation.

[joconnell]

In this vid from the lovely folks of Saddington Baynes who'd probably do a tonne of very small tweaks in post they're avoiding using any passes that cause problems - now the actual raw render looks gorgeous to start with so they don't need the extra control that raw gives. have a look at their vray buffer drop down to see what they're taking out - http://www.youtube.com/watch?v=Ahfr3g2QrTM

[Morne]

that's a nice set of buckets!