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Partially hiding geometry in C4D
I’ve got an object that’s basically a series of thin discs. At a certain point in the animation a couple of discs raise up to reveal a load of geometry underneath them, so I’ve used a couple of boolean objects to reveal that as they go up, otherwise they’d stick out below the lower discs.
Trouble is, this makes rendering *really* slow: whether using the basic renderer or Octane it’s taking about 2 minutes per frame. I don’t need to create new geometry, so is there a way to hide it similar to using a track matte?
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5 Replies
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can you post the file?
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I can’t really as it’s under an NDA. But I’ve done a bit more poking about to try and trap what was slowing it down.
It turns out it *wasn’t* the two boolean objects, nor was it the Xpresso. It was one line of MoText wrapped to a circle spline.
With the MoText: 1m43 per frame
Swapping the MoText for a standard text object, lofted (but keeping everything else on – lighting, shadows, Xpresso, booleans, best AA): 8s per frame!Is this a thing? Should MoText slow it down *that* much?
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The project’s moved on a bit, and I’ve ditched the booleans (as they seemed to slow things down a lot). I’m now hiding things mainly with transparent objects, then using compositing tags on the stuff that needs to be hidden with “seen by transparency” unticked.
However…. there are some objects that pass *behind* one of these transparent primitives. These need to be occluded by their *own* transparent objects, but *not* by any others. Here’s a quick mockup example…
https://drive.google.com/open?id=1iI_jKtAphZJoYlYI4o6riz1NWS5NCNEt
Currently, the blue cube’s compositing tag has “seen by transparency” unticked. This means that both the transparent objects in front of it matte it out:
https://drive.google.com/open?id=10PxflUBwRa57N5ZGTLSo9A75hUpYeCz5
I want to stop the foreground transparent cylinder from matting out the blue cube. I’d have thought that the way to do this would be to drag this into the “exclude” box on the cube’s compositing tag, but that doesn’t seem to do anything.
https://drive.google.com/open?id=1WeC3vJeZywFTDJTveeJ3ItlyskXOGOmc
Nor does dragging the blue cube’s transparent box into the compositing tag on “include”:
https://drive.google.com/open?id=1ATlVm0acwTDXrghJYEHR0JlMZYKnM7_i
Anyone know how to do this? Or is there a better way? (I’d rather avoid multi-pass renders as that might become a bit of a headache for a project like this!)
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FWIW, someone helped me figure this out:
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thanks for the follow up
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