How do I reduce these artifact and improve detail?

[thomthom]

I'm working on an interior render. Here's the last version:


As you see, in the ceiling, some of the holes are missing. It should all be uniform. Initially lots of them where missing, but I found that changing Image Sampler from Adaptive Subdivision to Adaptive DMC corrected most of this. But a few still remains. I did a couple of other tests where I increased the Min Subdivs and also Max Subdivs, but with no better result.

I also tried a larger IR Suvdiv and Sample value, no better result. Also tried DMC instead of IR (as is recommended for scenes with lots of glossy) but with no better result in regards to the holes. The holes in the ceiling is not modelled, but it's a texture.


Also, the horizontal lines in the wooden panel, I'd like them to be smoother and shaper. And I want to get rid of the Moire effect. These horisontal slots in the panel is modelled. 5mm wide.


Right now I'm doing a new render with higher IM settings and Image Sampler to Adaptice DMC, Min Subdivs 2, Max 32, Noise Threshold 0.005. (haven't tried adjusting the noise before.)


Can anyone give me some pointers to how I can correct these issues?

[dcauldwell_cg]

Re: How do I reduce these artifact and improve detail?

Thomas
Two suggestions you could try.
1 turn on 'detail enhancement'
2 Render at a higher resolution

A scene of mine recently kept loosing the lighting cables, because they where so thin, and rendering at a higher resolution definately made a difference.

Nice renders by the way!

David

[thomthom]

Re: How do I reduce these artifact and improve detail?

hm.. I haven't tried this detail enhancement. Will make a test with that.

While rendering in a higher resolution is a way to do it, I'd like to be able to control this with the current resolution. It's not just for this render, but for further reference and knowledge of V-Ray.


My new render with Image Sampler set to Min 2, Max 32, Noise 0.005 and IR of Sub 75 and Samples 30.


The holes in the ceiling are fine now. I suspect it's the Noise setting that did the trick. (Will test this further.)

But the horizontal slots still Moire...

[stefanq]

Re: How do I reduce these artifact and improve detail?

I think it's a image sampler issue, basically, the catmull-rom it's responsible for that...this is what I found about catmull-rom :
''Edge-enhancing filter, often used for architectural visualizations. Note that edge enhancing can produce "moire" effects on detailed geometry''
So, maybe if you change the catmull-rom filter, you will get better results....

[thomthom]

Re: How do I reduce these artifact and improve detail?

I'm not using Cat-Mull Rom. And Cat-Mull Rom is the Anti-aliasing filter, which I currently have set to off.

hm.. Maybe AA filter will help...

[thomthom]

Re: How do I reduce these artifact and improve detail?

I did a test, using same setting as with the first render I posted, but set the Image Sampler Noise Threshold to 0.005. But that didn't improve the ceiling either. So maybe it was a combination of the changes I did with the first.