VRay Black Outlines issue (Not caused by VRay Toon)

[Anonymous]

Hello Autodesk Community,

I am a Mental Ray Renderer main user who is trying to learn VRay due to the discontinuation of Mental Ray. I have a quick question that will hopefully be an easy fix. I am getting results in VRay that are unwanted. There are black outlines along the edges of my geometry that appear in VRay that do not appear in Mental Ray. I checked to see if I had VRay Toon enabled, and it is not enabled. 

I have a Mental Ray render sample and a VRay render sample for comparison. I want to achieve in VRay what is being shown in Mental Ray. 

I also checked to see if it was my environment studio that was affecting my reflections. The studio has a black ceiling and rear wall, and the rest of the walls are white within. This is not the cause of these outlines, and I will include a render sample from VRay with all of my studio walls being white to confirm this.Mental Ray SampleVRay SampleVRay_AllWhite_Sample

Any and all help is appreciated! Thank you!

[hagen.deloss]

Hi @Anonymous

Great to hear from you on the forums! I'm curious to see your material settings for these renders, is there any way you could post a screenshot of those properties so I can take a closer look? It looks like the specular highlights are handled differently per materials and renderer.

This almost looks like an anti aliasing issue, you may want to edit those settings, here is an article on those settings on the Chaos Group documentation. 

Speaking of which, I would recommend looking through their documents for more learning material here, and if you encounter further issues, you can contact their forum support here.

I look forward to chatting with  you further!

[miledrizk · Accepted solution]

Hi,

You can try quickly two possible fixes:

1- Use the VrayLanczosfilter filter in the Image Filter rollout as shown in the image below

2- If the first option didn't solve it, then try checking the option Sub-pixel mapping in the 

Color Mapping rollout as shown below

But I encourage you to check the links posted by @hagen.deloss for more understanding about the issue.

[Anonymous]

Thank you guys for your quick responses!

It worked! It was as simple as changing my Image Filter. I had it set to Catmull-Rom, which was probably the cause of these black outline artifacts. Changing it to VRayLanczosFilter managed to mitigate those issues and give me comparable results to my Mental Ray samples. 

I'd say I wish I would have tried this earlier, but asking the forum introduced me to the Autodesk community. So I take this as a silver lining. Thank you again for your help!