nested vray object properties issue?

[jasonhuang1115]

Hi there,

In a scene there is a car with hood open and its engine visible to the render cam. If you assign Object IDs to different small groups of engine parts geometries to generate mattes via several vray object properties nodes and meanwhile want to make the whole engine (which is comprised of all the small groups of geometries) "Not Visible to GI" and "Not Visible in reflections", what would you do to achieve this? I tried assigning another vray object properites node to the whole engine, but it doesn't work. Is there a handy way to achieve this level of control in terms of custom object properties.

I tried to wrap my head around this but kept hitting the wall.....

Thanks!

[vlado]

You could add the object IDs only separately on a per-object basis as V-Ray extra attributes.

Best regards,
Vlado

[jasonhuang1115]

You could add the object IDs only separately on a per-object basis as V-Ray extra attributes.

Best regards,
Vlado

However, this is what I try to avoid as, if doing that, I'll have to assign object IDs on a per-object basis for more than hundreds of objects. That's really inefficient. I can opt to use material ID for setting up mattes, but still a finer control is desired when I need to separate the mattes for groups of objects with the same material assigned.

[vlado]

I'll have to assign object IDs on a per-object basis for more than hundreds of objects.

No, you don't have to do that - you can assign the Object IDs to group transforms as well.

Best regards,
Vlado

[jasonhuang1115]

I see. This does provide a better approach. But it also means that I have to group objects exactly the way I want to assign object IDs or mattes. If groups are structured differently by a modeler upstream, then the lighter needs to wade through the process of re-structuring the groups, if it's allowed in a production pipeline. Or, am I still missing something on this?

[vlado]

Well, if even that is not acceptable, you can apply a separate VRayObjectProperties node just for the IDs - enable its "Override Object ID" option, and also turn on its "Disable" option so that they don't try to modify the visibility flags (although I'm not quite sure if this will work as I haven't tested it).

Best regards,
Vlado

[jasonhuang1115]

Well, if even that is not acceptable, you can apply a separate VRayObjectProperties node just for the IDs - enable its "Override Object ID" option, and also turn on its "Disable" option so that they don't try to modify the visibility flags (although I'm not quite sure if this will work as I haven't tested it).

Best regards,
Vlado

I just tested this approach, but unfortunately, the MultiMattes_RE turns out totally empty/black. Guess there is still something/flag conflicting with each other internally.

[pechart]

I'm having some issues with this, too.
I have some obj.properties for several groups and objects where I override their IDs. Those are grouped under a supergroup.
On a seperate renderlayer I want The supergroup to have the primary visibility disabled, so I Disable all other obj.property nodes on this layer and assign a new object property to the supergroup in which I disable the prim.vis. flag. But nothing happens, the object renders with prim.vis. on. When I delete the disabled object properties for the subgroups everything works as expected.

EDIT: Oh, and when I set the prim.vis flag on the objects itself in the maya attributes it works, too.