Final Gather and "Use Background" in 6.5

[Phil_Boy]

Hmm, I don't know if this is possible with mental ray, but in Turtle, for every object there's a section in the attribute editor saying: "Turtle". Under that, there are attributes where you can switch e.g. Cast FG, or Cast GI, either on or off.
Maybe you can find this in mental ray somewhere and use these attributes to correct you objects.

Hope I could help,
Phil

[=OverDrive=]

I don't believe Mental Ray supports Maya's background shader. That is unless it's one of the updates in 6.5. I read somewhere that it's overcome by using a combination of the maya's renderer (to use for the backgroud shader only) and mental ray's renderer (for everything else). Then just use compositing program to combine shadows and such.

O|D

[bgawboy]

Not sure exactly what you're trying to accomplish, but each object's shape node
has an FG cast and FG receive toggle under the mental ray tab.

Do you want regular ray traced shadows, but not 'FG shadows'?
In other words, the light from FG is not attenuated by objects occluding light?

[bgawboy]

Playing around with the Use Background a bit, I thought I'd give a possibly clearer explanation.

If you look at just the alpha channel, you can see where the light from FG effects the
objects with Use Background. If you turn off FG receive on the shape node of the object with the Use Background material, the FG effect will disappear. My guess is that is what you want.

[Jozvex]

Actually I think he needs to turn off cast FG on the objects with the Use Background shader!

What he's saying is that his 'Use Background' objects are not only receiving FG shadows from the 'real' object, but they're casting FG shadows onto each other as well.

And yes =OverDrive=, in the 6.5 update they made the Use Background shader support FG in Mental Ray.

:)

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