View Full Version : Reflect but not visible in MR???
12-19-2003, 01:25 AM
Okay, maybe I'm missing something in the docs (the docs....that's a laugh), but I can't seem to get MR to deal with render flags correctly.
I'll describe the problem using a simple scene:
I have a reflective glass sphere under a dome.
I want the dome to reflect but NOT be visible through the sphere.
I turn off Primary Visibility of the dome, leaving on Visible in Reflections.
I turn on raytracing in the MR render globals.
I render the scene, and what do you think I see through the sphere? You guessed it! THE DOME!
Anybody have any insight into this? It's driving me nuts!
12-19-2003, 11:12 PM
I had a similair problem with reflections always showing up when rendering with mr. I think you can pretty much forget the usual render stats flags when you're using mental ray.
Go to the object (not the Shape) node in the attribute editor and open the mr rollout. Open the Flags rollout (I think it should be open by default) and uncheck the "Derive from Maya' option. I think there's a thing in there for visibility. try setting it to off.
12-23-2003, 12:07 AM
Unfotunately, it's no go.
Turning the visibility off still allows the object to be visible through the sphere.
I do believe this development oversight qualifies as 'sucky'
12-23-2003, 01:41 AM
When something is visible though something else, especially if it is through something refractive and you're raytracing, then that isn't primary visibility - primary visibility means seeing it directly, not refracted through or reflected off anything else.
Try scaling up the dome, and putting another surface behind the sphere, then you should see that surface through the sphere, not the dome. You can use a "use back color" shader on the new surface if you want, to keep the alpha transparent.
(If all you want is a dome reflection, it might be faster to skip the raytracing and just map the image on the dome to the upper half of a spherical environment map on the sphere material's reflected color, though.)
12-23-2003, 01:51 AM
Or a couple render pass might do the trick...
12-23-2003, 03:24 AM
That's the workaround I'm using currently. What's really irking me is that the sphere is not refracting at all. This is purely a matter of reflection without visibility through a transparent object.
Ah well, at least it looks good in the final comp.
Thanks for the help guys!
01-17-2006, 12:00 AM
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