Triangles in render, not in SketchUp model

[Headroom]

The issue is the very long thin triangles. In Blender I'd add a few knife cuts to make these triangles shorter. I think I remember that another SU user had a similar problem and was able to fix it in SU.

With a little luck he may answer in this post. In general it would not hurt to try the latest Indigo version

[bioman666]

Thanks, i've managed a workaround at minimum cost (in my situation, it might not suit all cases) :

• 1. The bigger the scale (large bumps in materials) the better
  2. The darker the material color the better

I'm baking a render right now, i'll post the end result tomorrow.

[CTZn]

Your Indigo is up to date, is it ?

Almost. 3.2.13, but I haven't read anything on this bump issue on changelogs to date.

Fair enough. Indigo has seen some improvements on this front but they are older than that.

[Coen Naninck]

You can also try to offset the outer profile Edges if you're working in SketchUp. You can do that with a plugin called ToolsOnSurface by Fredo6 on the SketchUcation forums. Or you can stamp a rectangle into the surface and hide the Edges, then export. That should make the triangles smaller.

[bioman666]

Ok here's what i got to date. Obviously, frequency of the noise shader matters when it comes to this bump issue.

You can also try to offset the outer profile Edges if you're working in SketchUp. You can do that with a plugin called ToolsOnSurface by Fredo6 on the SketchUcation forums. Or you can stamp a rectangle into the surface and hide the Edges, then export. That should make the triangles smaller.

Thanks I'll try this later, I don't have enough time right now and using some photoshop i can get a mixed image of both bump shade frequency without all the trigangles thing, so it's ok to me so far.

[OnoSendai]

Hi bioman666,
Can you please send me the scene showing the artifacts as a PIGS file?
thanks!

[bioman666]

Hi Ono !

Here's the troulemaker : https://www.dropbox.com/s/e04hminfeyx1s ... ngles.pigs

Have fun...

[OnoSendai]

thanks!

[Coen Naninck]

I downloaded the file and see the issue at the front. If you draw some rectangles around the screws that should fix at least some of the issues, but I can't say for sure. If you turn off the bump feature in the material used the issue should resolve itself altogether (you did use bump on it, right?).

As an aside, I love how beautifull Indigo renders the otherwise plain looking object (don't mean that in a condescending way btw). Indigo indeed IS a great renderer.

[CTZn]

Ok here's what i got to date. Obviously, frequency of the noise shader matters when it comes to this bump issue.

In fact when you change the frequency the height should be changed inversely (twice the frequency gets half the height).

One way to set bump right is to set the right-looking height ratio on a (very) low frequency version, then do the height maths for the final density.

From the render I can now say that the high frequency noise features are higher than their caracteristic width, if that's making sense. It's stretched really.

edit: I'll add this: you formerly recreated an Oren-Nayar-like surface, with a pretty high roughness. Probably beyond the sigma limits.

[bioman666]

In fact when you change the frequency the height should be changed inversely (twice the frequency gets half the height).

Mmm that explains a lot. Thanks for the heads up !

From the render I can now say that the high frequency noise features are higher than their caracteristic width, if that's making sense. It's stretched really.

Do i get this right (see my translation into graphics) ?

edit: I'll add this: you formerly recreated an Oren-Nayar-like surface, with a pretty high roughness. Probably beyond the sigma limits.

You mean Oren-Nayar is a useless waste of CPU when roughness is set this high ? I've used this blended Oren-Nayar/phong material as found in the "rippled plastic" material in the Indigo material library, and I've not tested it extensively.

[CTZn]

From the render I can now say that the high frequency noise features are higher than their caracteristic width, if that's making sense. It's stretched really.

Do i get this right (see my translation into graphics) ?

Absolutely right. I'm proceeding visually myself at this stage, just ensuring that the bump mapping is not producing harsh shadows before I augment the frequency and scale the height down accoedingly.

edit: I'll add this: you formerly recreated an Oren-Nayar-like surface, with a pretty high roughness. Probably beyond the sigma limits.

You mean Oren-Nayar is a useless waste of CPU when roughness is set this high ?

No, using an Oren-Nayar material would be faster in all cases I assume. I meant that there is no way to have such a rough material in Indigo withot using ISL as you did first.