Strange Artifact when Rendering

[blueman26]

Using Sketchup 17 and V-Ray 5.2

For some reason, I am getting a line of lighter material when rendering this object. It's a solid object and it seems to occur with any material I use.


Here is the sletchup window



I removed all materials and tried it again with different materials and got the same result


I've tried moving the model to see if it had something to do with the lighting or reflections in the scene but it still showed the artifact.
I tried painting face and did not see the artifact. I can't find any issue with the object. If someone can point me in the right direction, it would be much appreciated.

Thanks

[Peter.Chaushev]

Hello, blueman26 ,
Hard to tell what is causing the artifacts based solely on illustrations. Does the issue occur if you substitute the wood material with another one?
It would be faster to solve this by having our Support team investigate your model. Can you please share it (or at least isolate the faulty part and send a copy of your model) either directly in this forum thread or via https://support.chaos.com/hc/en-us/requests/new ?

[wzfwzfwzf]

This image error should come from the circular hole . Try removing the coplanar lines or removing the smoothness.

[blueman26]

Thanks I just tried that, merging coplanar using "CleanUp" and also softening the edges, but it still doesn't work. It does make sense, because of the location of the curve, but so far, what I tried did not work.

[blueman26]

Also, when moving the camera position to the middle of the board, the line seems to move upwards and then dissipates by the time you move the camera to the other end of the board

[wzfwzfwzf]

You need more line subdivision models

[wzfwzfwzf]

You need more line subdivision models。

[blueman26]

That did seem to work. Thank you. All I did was to simply draw a line from one edge of the face to the other.
Can you please explain why this is necessary and what the rule of thumb might be so I can make sure that models in the future meet this requirement for rendering properly? Also please let me know if there is a better method to use than the simple fix I employed. Thanks again

[wzfwzfwzf]

I guess This may be related to the nature of the SKETCHUP surface. The pseudo-quadrilateral surface is composed of two triangular surfaces. If there are small round edges, many triangular surfaces will be gathered together. Causes some problems, then it needs to be subdivided

[blueman26]

Ok Thanks again, so I guess if there are small rounded edges again in a model, I will give it a couple of subdivides before rendering.

[konstantin_chaos]

Hi blueman26,

I would also recommend adding a couple internal edges manually before rendering.
This should resolve the issue.

Konstantin