problem with instancing!

[azshall]

I'm using Maya 6.0.1 ... When I turn OFF 'primary visibility' ... it does just that (say for reflections, etc) ... However, when I have instanced objects, and I select the object(s) that are BEING instanced, and then turn their primary visiblity off and do a render, they are still there!

Is this a bug, it doesn't seem right to me? Or is there anyway around it?

Seth

[bart]

So you turn off visibility at the shape node (object), but have it on at the transform node (instance)?

For flags the lower level instance overrides both higher level instances and the object flags.

I'm not infront of Maya right now. Is there a choice to use inherited for the transform node for visibility? You might have to check off 'Derive from Maya'.

Its in the flags section of the mental ray tab of a transform node.

BTW, I'm making a Flags tips page because this stuff needs better doc overall.

[azshall]

Hey bart.

Yes, I did turn off the visibility within the 'Derive from Maya' section.

I need the visibility on for the Instancer Node. I need it off for specific objects in the instance so that I can get my reflections but not the objects in the actual render.

This currently works with Maya Software, not with mental ray. Now, remember, I'm in Maya 6.0.1 and I haven't tested on Maya 7 (which I can't for this project), so it may work there? I do not know ...

Wasn't sure if there was a work around or if this was discovered, thanks!

Seth

[bart]

Sorry, but I'm confused a bit with your terminology, and I'm not sure what an instancer node does.

You mention multiple objects for an instance, which is not possible without some tree of connection. Usually there are multiple instances of an object. (Multiple transforms nodes refering to the same shape node.)

Do you mean that you have an instance of a group of objects?
The actual mental ray DAG would have an instance of an instance group which contained instances of objects. In maya, it would be a transform node of a group which contained transform nodes each refering to the same or different shape nodes.

You could turn off visibility at the instance (transform node) level just above the object (shape node).

Or if you use inherited at all your instances, then you could control visibility at the object (shape node).

[azshall]

I'm actually using the Particle Instancer.

I've created a grid of about 270,000 particles. I've got a LOD locator setup so that I have a highres Instanced Object near camera, Mid res object about a 1/3 of the way back and beyond that is all Low Res ..

This uses 1 node within maya. It basically populates the particleShape (by using the individual particle ID essentially) with a piece of said geometry (or whatever you decide to instance).

Now that I've got my Particle Instancer node with all of my objects, I want to render each section in seperate passes. ie, High Res, Mid Res and Low Res. I want to get reflections of my HIGH RES objects into my MID RES objects. I do not want them to render, so I'd use the Primary Visibility flag in the Shape node of my instanced High Res object.

Doing this in MR works fine, but not with the particle instancer. If I render my instanced object with Primary Visability OFF it will still render my object.

Using Maya Software renderer and this same technique works fine, problem is, its not MR. I need MR :(

Does this make sense? I'm not actually using instanced objects, its an actual node in Maya called the Particle Instancer, its kind of a blackhole/unknown thing. It works, it can do what you want, but there isn't much information out there on digging deeper with it unfortunately.

Seth