Stonemason buildings, minor problem

[acc24ex]

change the values to see if you get rid of the glitches, not sure whats going on there but it helps on occasions

[Jools]

I can often solve geometry problems in Octae through (DAZ viewport:) Parameters>Mesh Resolution>Subdivision Algorythm. Especially Catmull-Clark (legacy) and Bilinear can do a lot.

[UruMike]

Hello Erik

Looking at your original picture I think this is a rayepsilon problem.
To be honest I'm not really sure what this setting exactly does, but I had these weird dark forms in my renders also from time to time.

Just load the scene, increase the value (try x10, so a value of 0.00001 becomes 0.0001) and render, see if it helps. You may have to increase more.

Good luck!

[Jazbee]

For all of you wondering what rayepsilon actually does (this is from the Octane standalone manual):

Ray Epsilon(rayepsilon) - The ray epsilon is the distance to offset new rays so they don't intersect with the originating geometry. If the scale of your scene is too large, precision artifacts in the form of concentric circles may appear. In that case, increasing the ray epsilon can make these artifacts disappear.

Also some more info from the troubleshooting section of the said manual, which might prove useful:

6.5 Render Looks Strange or Gives Unexpected Results

Problem: Concentric circles over the image or unusual effects including bump map not working
Solution: Check the scale of the imported scene and change the rayepsilon value. Typically this is due to the scale being incorrect by a factor of 100 or 1000X. Octane expects 1 unit in the scene to equal 1 meter. Adjust export settings in the modeling application or adjust the import settings in OctaneRender™.

Problem: Facetting occurs revealing the underlying polygonal mesh, Geometry or Normals issues
Solution: Ensure that the geometry and normals are correct in the modeling program. Re-export the scene if necessary. Make sure the Normal Smoothing boolean value ("smooth") is enabled for each material in the Node Inspector.

[dsyee]

@ acc24ex
No, I haven't yet, mostly because I haven't got a clue (yet) what it does.

First thing I want to try is remove any stacked layers of geometry and see what happens.
These two buildings appear to have kind of an odd structure of wall and window layers which could possibly make the surface 'undefined' for Octane.
Again, these buildings render just fine in LuxRender.

As for those crashes: I'll try that Latency setting Linvanchene suggested, perhaps it helps improve stability.
Thanks for the help guys.

Cheers!

Erik

Don't do all that crazy stuff! Take everyone's advice and adjust your rayepsilon settings first. I am 99% sure this is a rayepsilon issue.

Here's an example stonemason scene:

rayepsilon = 0

rayepsilon = 0.00001

Looks exactly like your problem, yes?

Reduce the rayepsilon setting for closeups, increase it when the scale is large.

[Spectralis]

I've had this problem with sky domes and large textured areas. I'll try some of the suggestions to solve it.