Yucky render with invisible to camera

[tricky]

I have some trees in a scene that I don't want to be visible to the camera, so I go to 'properties' of the objects and tell them not to be visible. However, at render time, I get a dirty edge. Why is this and how can I get rid of it? It is a high poly object so I guess it could be coplanar, or overlapping leaves within the object.

[chrisjacks21]

Hi tricky, I have had this before. As you say I think it is an issue with GI and coplanar geometry. Maybe also try disabling GI on the tree in Vray properties...

[instinct]

Hi there,

secondary ray bias sometimes helps in these situations.

Regards,
Thorsten

[tricky]

There is no GI in this scene - just a vray sun and ambient light.

Will try the secondary ray bias - would that have any detrimental effects on anything else - render times for instance?

[dlparisi]

Did you uncheck "visible to camera" or "Renderable"? Could it be refraction or reflection on the leaves of the other leaves?

[tricky]

Could it be refraction or reflection on the leaves of the other leaves?

Could be that I guess. I will try to turn off reflections and see what happens. Good idea!

[rikou]

Do you solved your problem Tricky ?
I have a similar situation with trees (proxy) with opacity maps for leaves, all trees are not "visible to camera", etc.
I've got the same artefacts...

[Deflaminis]

Try turning off map filtering for your opacity maps...

[tricky]

I'm afraid I didn't even get a chance to try the idea suggested - we ended up painting out the problem.

[rikou]

It's not about opacity in fact.. I have same problem with a default vraymatl so nothing to do with matl.
In fact, the only way to avoid those artefacts is the secondary ray bias as said Instinct...
it's exactly THE problem... coplanar faces with leaves I mean
But I have to raise a lot the value, too much in fact ... too much and this leads to others problems so it's not a solution
I have to find another way to go...

[duke2]

I've recently run into this and it's a huge problem. If I fiddle with the secondary ray bias, the transparency bias and transparency levels, I can reduce it, but nowhere near eliminate it. In order to do it properly, I have to reply every single material over the VRayOverrideMtl, and then if 2 objects share the same material that I want to separate, i'd have to duplicate the material. This is utterly unworkable. I really hope there's a fix in the pipeline (so that Visible to Camera disabled renders the same as if the Render Material (not GI, refl/refr, etc.) were null).

[tashko.zashev]

Hi George,
Could you post an example scene that reproduces the issue so we can test with it.
Thank you