Cloud render black blotches

[Anonymous]

Hey, I'm just starting to get into rendering, and need to have Alpha / Transparency background, as well as very clean/realistic nonjagged/anti-aliased edges, so am attempting the cloud rendering, but always get areas of black blotchiness, such as shown in the below image (notice it on the bottom of the front diagonal yellow stick).  

I can fix these areas in a photo editing program without too much trouble, but was curious if this is a known issue at all and possible remedies.  I've also attached the .f3d model. 

Thanks!

Jesse

[Anonymous]

It looks like changing the material from opaque to translucent (glossy plastic) helps.  By the way, this is really great, for product packaging and what not, even though I've been so focused on the physical fabrication aspect!

Jesse

[hutchij]

We're investigating, This is really strange, maybe a geometry issue. Stand by. 

[Anonymous]

Hey, thanks for looking at it!  Overall I've been blown away how straightforward it is to make and render these photorealistic models.

Jesse

[anavaidya]

Hi Jesse,

This looks like a geometry issue and is not specific to the Cloud renderer. It also happens with local raytracing. We are still investigating and I'll update you when we know more.

[anavaidya · Accepted solution]

Hi Jesse,

This is in fact a geometry issue. Since you created your pipes using Model -> Create -> Pipes, it is resulting in really thin long triangles at the time of render and results in black artifacts that you see in the image. The workaround is to model from the Scuplt workspace. Sculpt -> Create -> Pipes. This will result in a smooth mesh. I tried it here:

More information here.

Let me know if this suggestion helps you and if you need additional information.

Thanks,

[Anonymous]

That did it, this will help so much! 

Thank you!

Jesse