HAIR render multipass

[thomastraum]

Is there a way to render hair with a multipass. I tried the usual approach of using render layer IDs but while other elements work hair doesn't seem to come through. Also doesn't show up in obejct ID passes

[aoktar]

If you talk about Octane's native hairs, they are 3d geometry type not a post pro effects as in C4D. So they should work as other geometries. Are you putting some object tag and give some layerID>1?

[thomastraum]

I believe so. Works fine with normal geo but comes out black on objectID layer 4

[aoktar]

I have to say sorry. I think hair engine has a ignorance for objecttag's some parameters. Haven't thought that would be required.

[thomastraum]

Actually I revisited the scene yesterday and it works now... not sure what happened. Either way it totally shows up in the MP.

[aoktar]

Actually I revisited the scene yesterday and it works now... not sure what happened. Either way it totally shows up in the MP.

I'm curious how could you do? It can be useful for my fix.

[jjmotionstudio]

I found this thread after searching for a solution for this -

To make Hair show up in a Render layer mask, do you have to assign the Hair directly to a render ID? When I try to put an Octane object tag over the entire null containing the geometry and the Hair, it comes back fuzzy (no pun intended) and doesn't mask the entire object as expected. Do I need to make sure an Object tag is on everything (geometry + hair) instead of just over the whole null?

See attached image below. The Bunny geometry and hair tag is grouped in a null with an Object tag designating the whole group as a render ID. The image is fuzzy and noisy, not putting everything in the tag. In fact, it looks like it's specifically subtracting the hair.

[aoktar]

jjmotionstudio
Don't check edges on picture viewer. You'll see expected result on a compositing software.
About hair, are you not on a latest version? It's fine with that.