Foam vs VRayZDepth

[3dwolf]

Is there an issue (known or already fixed) with foam and the VRayZDepth-Element?

Foam renders blackish.
PHX nightly 25954 here
VRay 3.10.03

[Ivaylo Katev]

you have to use geometry mode for the foam, in max only the geometry can produce a z-pass

[3dwolf]

Aye, much better, thanks. Foam and splashes set to GeoMode now.

... but:

[Ivaylo Katev]

still white zones are existing, in the ideal case the foam must disappear in the z pass, because is near to the liquid z value.
but the z pass of transparent objects is an illusion, my suggestion is to get the z pass by second render, with foam and all the lighting switched off.

[3dwolf]

Yep undefined became different off-Z. I was hoping to get everything in one pass to save some rendertime.
"Updating Object PhoenixFD" takes 40 seconds in this scene; ... that is not so super long but adds up. I will find some other elements to add in so it makes more sense to render an additional utility-pass.
Thanks.

[Ivaylo Katev]

you can try some tricks. return the foam in atmosphere mode (it's z pass is not needed), and try to remove the black zones. i think the black areas appear because vray skips the rendering of the geometry, considering it fully invisible. there is an option "transp cutt off" perhaps it can solve the problem, if you set it to zero. just a suggestion, never tried this

[3dwolf]

Didn't get that to work.
But if someone wants to render out clean Z- and whatever-Elements with Foam, set it's Refraction Index to the max (10) in Geo-mode and it will give proper results (except a nice beauty-pass :P )

[Ivaylo Katev]

excellent idea, will suggest it to the other users having the same question.