Displacement Issues... Bug or User error :) ?

[valkama]

Hello. I am having difficulty getting displacement to work in VRay. Please see attached image on what i am seeing... strange wavy artifacts on the seam edges. Does anyone have an idea what i may be doing wrong.

Thank you!

[thomthom]

Re: Displacement Issues... Bug or User error ?

By default, displacement quality is View Dependant. (You'll see the checkbox checked in the Displacement section in the Options window.)
When this is on, Edge Length is the length in pixels and the default is 4. Try reducing this. Note that when you lower this render times and RAM usage increases. So find a balance.

[valkama]

Re: Displacement Issues... Bug or User error ?

Thanks for the reply.

I actually tried with edge setting numbers from .1 to 40 both with view dependent checked and unchecked. That actually did not change the result at all. Rendering looks the same no mater what edge setting i change too? Do you think it could be the map?

Thanks!

[valkama]

Re: Displacement Issues... Bug or User error ?

Im just wondering if anyone is getting good results for displacement from elements that are more linear in nature, like these lines?

[valkama]

Re: Displacement Issues... Bug or User error ?

Has anyone been able to get accurate displacement similar to what i am showing using Sketchup?

Thanks

[thomthom]

Re: Displacement Issues... Bug or User error ?

FYI, when you use displacement maps that are 8bit per channel V-Ray applies a gamma correction. (the default settings dot his.)

There are more info on what is going on at this SCF thread: http://forums.sketchucation.com/view...189538#p148769
(you might need to login to see the attached images)

Also related: http://forums.sketchucation.com/view...22687&p=191705

[thomthom]

Re: Displacement Issues... Bug or User error ?

It's possible that the counter gamma adjustment is not needed on 1.48.66+ - have not fully investigated this.

[thomthom]

Re: Displacement Issues... Bug or User error ?

Posted a sample here: http://forums.sketchucation.com/view...?f=322&t=28593

Sorry for posting the sample in another forum, but it was just easier to upload files there - plus there has been V-Ray users asking questions about displacement there as well.

[dkendig]

Re: Displacement Issues... Bug or User error ?

::mumbles about not being able to easily post images::

[valkama]

Re: Displacement Issues... Bug or User error ?

I checked out the sketchup forums. Thanks again ThomThom for your great advice!