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Author Topic: Edge mode rendering shadows of "clipped" objects  (Read 4642 times)

Macker

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Edge mode rendering shadows of "clipped" objects
« on: August 22, 2017, 05:58:36 PM »
Hey guys,

I'm running Forest Pro 5.4.0 and I've got a really strange issue with geometry rendering in edge mode... It's rendering the shadows of objects that've been clipped/trimmed to edges, even though it isn't rendering the geometry. See image for example.


Michal Karmazín

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Re: Edge mode rendering shadows of "clipped" objects
« Reply #1 on: August 23, 2017, 10:30:29 AM »
Hi,

That's most probably related to the default transparency limit value, like in this one: "White pixels on Forest grass with edge mode enabled"

"... V-Ray exceeded its default transparency limit (which could cause similar render artefacts). I would suggest you to increase Global switches - Max transp. levels (default value is 50). Sometimes may be necessary to modify Secondary rays bias also.

As mentioned in this "Some key notes about Areas->Boundary Checking->Edge mode" related post: "In the case of very high density scatters (like dense grass), many overlapping objects could be generated and V-Ray may exceed its default transparency limit (which can cause render artifacts)". You can find there how to fix it (use lower Density values / increase VRay's Max transp. levels)."


Hope that helps.

Best regards,

Macker

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Re: Edge mode rendering shadows of "clipped" objects
« Reply #2 on: August 23, 2017, 12:13:17 PM »
Hi, thanks for the reply.

I'm not entirely sure that is the issue (I've experienced that one before and was able to fix it by adjusting the max transparency setting).

This one appears to be different, as I'm not seeing through to the VRay Sky as the previous would cause - the blades of grass seem to be casting a shadow. Not only this, but the grass itself isn't particularly dense; the density map is set to 22000mm. File attached here:

https://we.tl/Q63dGnByeA

Michal Karmazín

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Re: Edge mode rendering shadows of "clipped" objects
« Reply #3 on: August 23, 2017, 01:56:44 PM »
Hi,

Thanks for the provided scene. Which V-Ray version are you using? In V-Ray 3.60.01 & 3.60.02 there is a similar issue reported and switching off Embree should fix it. Upon our quick internal tests, the V-Ray 3.60.03 doesn't suffer this issue. Hope that helps.

Best regards,

Macker

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Re: Edge mode rendering shadows of "clipped" objects
« Reply #4 on: August 25, 2017, 10:32:02 AM »
I'll check, thanks for the reply.