strange Polygon Lines / Edge-Shadow Problem

[atin]

Sorry I installed an older version last time I was here at my workplace, thats why it crashes now, It was just my fault. Could you send me the link to the actual version I should use, please? Then I will try terminator...

[houska]

The link is in this forum thread: https://forum.corona-renderer.com/index.php?topic=18711.0

The link itself (you'll want rc2): https://drive.google.com/drive/folders/1rUctswGPIeucE9JtjdQrzY3JZq67HNgw

[atin]

Thanks!

I dont want to be picky, but look at screenshot 5, I think in the back of your render, the same issue appears I think...

[atin]

Issue is still there when you rotate camera ("6"), from the position you rendered it looks good in my scene, too.
Phong Tag (+ a bit of terminator) assigned gives a bit of medicine but it is still not good. ("7")

[houska]

You're right... I inspected the model a little bit more and the problem is that your geometry is not perfectly coplanar, so artifacts can appear, exactly as they would in real life...

I suspect that in your HDRI map (which cannot be extracted rom the .rar by the way), you have a sun, which is hit only by some polys, depending on their normal. This is why some of the polys of the geometry are lighter than others. You should fix your geometry.

[atin]

Oh man, 3D is just  its own science ^^
Sometimes I think about getting back to oil paintings

[atin]

So I have another Problem with this issue, on "L1" you see a round modelled Leg, modelled in Zbrush , maxwell and C4d rednder have no issues. When I render it in Corona, it looks like a very hard edgy "reflective" cute that crosses the model.

Please help, I love the render engine, but it seems not usable at this point to me, but mybe its my fault.

"L3" is with reflection turned complete off, so its not a reflective issue. The Bump Map covers everything perfect.

[houska]

That is again pretty strange. Could we see the scene again? :-)

[atin]

Sure, here, reflection is still unticked in material editor. Thank you!

PC: I7 3770, 64bit, Win 7 Pro
C4D: 17.016

[houska]

You have unnecessarrily complex lighting setup there. Just remove all the cuboids with light materials and you should be fine...

[atin]

Okay it was the outside of the airplane light, don't know why. Now I have 4 Lights left, i want to have this, like a kind of product-photo studio setup...

Without the outside box it works now.

[Eddoron]

The armrest didn't have a phong tag, just adding one with standard 40°  settings solved that.(i also broke the ngons and reconnected the broken phong edges)
It was not a corona issue because the artifacts were visible in the editor window and standard render.
But as Houska mentioned, the polygons are not perfectly coplanar and some are hidden under n-gons.
Selecting a few of the points and decreasing the aberration in distance can solve that too.
Also, when not working with quads, be careful with bevel tools.
I'd advise you to create the armrests through SubD modeling. That should go really quick as you only need a few cuts and it keeps the mesh clean.

As for the leg...it looks like a (uv-)mapping problem(eg: a seam) but it could be anything. Can't tell without inspection.

edit: oversaw the leg scene. disabling the 2 side cube lights solved it. But the model didn't have any UVs. Since it was created in Zbrush, you can easily do that with UV Master. Just make sure, the seams are in positions where they won't be visible.

edit2: i obviously didn't read clearly, that some issues were already solved. So just disregard the most but look at what I wrote about topology&UVs.

[atin]

Thank you all very much (;

Have a nice wekend!