FP7 + VRay proxies - breaks matte extraction tools (works in FP 6)

[RM2551]

If VRayProxy(s) are used as source geometry then all instances will have a Node Render ID of 1 in FP 7. You can visualize this using the VRayRenderID channel.
In FP 6 the instances would have the node render ids of the respective source objects. (Tested with 7.0.4b and FP 7.0.6 + V-Ray 5.10.00 build 00001)

This change breaks the following tools that can extract mattes/masks based on node render ids:

• psd-manager (Masks from Objects, Selection Sets, Layers)
• MultiMatte render element (include/exlude lists of objects)
• CryptoMatte render element (node name, node name and hierarchy)
• RPF files

The resulting masks are unusable to select specific source geometry or specific Forest objects. There is only one giant mask showing all proxies in all forest objects regardless of the source object chosen. The issue is further complicated by the fact that the id 1 assigned to all instanced proxies is not even free to use, because one object in the scene will likely already have id=1 assigned at render time. So this other random object will also pollute the mask. So these masks are not even usable as a global mask of all forest objects.

This change also influences other rendering/post production features, since Node Render IDs are widely used in 3ds max. For example
VRayToon uses INode::GetRenderID to include/exclude objects.

A customer alerted me of this issue during the Beta. I think FP 7.04b partially solved this for other kinds of source objects, but the issue is still present for vray proxies. I also see the same problems with VRayInstancer.

Regards,
Daniel Schmidt - psd-manager Developer

[Paul Roberts]

Hi Daniel,

Thanks for your detailed report on this issue. We're looking into what can be done. As you've mentioned V-Ray Instancer suffers from the same issue, and we're now using the same approach in Forest Pack 7. It may be we need to Collaborate with Chaos. Hopefully though we can fix it soon.

Many thanks,

Paul

[RM2551]

For completeness let me add a feature to the list affected by Node Render ID problems: V-ray Image Sampler Render mask

This is affected in all object based modes (Selected, Layers, Include/Exclude Lists, Object-IDs). Internally V-ray probably first collects a list of Node Render IDs that are then processed.
As a result you can not isolate rendering to a specific source object when using V-ray proxies as source geometry. Also some other seemingly random object (that has node render id=1) may be rendered as part of the selection. If the render mask happens to include the object that has id=1 then also the proxy instances created by Forest will show up (since these always have id=1 too).

Regards,
Daniel Schmidt - psd-manager Developer

[Paul Roberts]

Thanks for the update, we've just had that reported from another user too. It would appear to stem from the same issue. We're looking into it.

All the best,
Paul

[TQ2169]

Yep,

Just got the reply from Paul, and happens on this side also.

looking forward to see this solved!

Best of luck,
João

[RM2551]

Thanks fot the fix (by reverting to the previous handling) in version 7.0.7.
What are the disadvantages of the old way of instancing?

Regards,
Daniel Schmidt - psd-manager Developer