Author Topic: Artifacts with Render To Texture  (Read 2625 times)

2020-07-20, 18:58:56

edredar

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Hi. I'm using Corona primarily to generate lightmaps via Render To Texture dialog. Three days ago I've stumbled on problem, I can't solve whatsoever. When I just regularly render the scene - everything looks ok. But when I try to render Corona_Beauty in RTT - I get tons of artifacts in the corners of the plinth. I've checked everything I could, tried everything I can think of - UVWs, Smoothing Groups, Normals, every render setting in the Corona, different Corona versions - and no luck, unfortunately. You are my last hope to solve this problem. I'm using Corona 5 Hotfix 1 and 3DS Max 2017 (or 2020, same story). I attach the scene and the bake result.
« Last Edit: 2020-07-21, 12:03:45 by edredar »

2020-07-21, 11:39:51
Reply #1

maru

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NOTE: The scene is infected with a 3ds Max virus!!! Please run Prune Scene and/or Sini Forensic to get rid of it! I would also suggest scanning other scenes and / or folders to make sure you do not infect other files!
I removed your attachment, but have it on my HDD.


Other than that:
Can you please provide the exact steps how to reproduce the issue?
Which object to select?
How exactly should it be rendered?

Ok, managed to reproduce it. Looking into this.
« Last Edit: 2020-07-21, 11:46:42 by maru »
Marcin Miodek | chaos-corona.com
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2020-07-21, 11:57:20
Reply #2

maru

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Looks like the issue is related to the geometry itself and automatic UVW unwrapping. Please try these things:
1) Subdivide the mesh using, for example, the Subdivide modifier
2) Change UVW mapping - e.g. apply automatic Box mapping or some other mapping type

Here is my result after using the Subdivide modifier.
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2020-07-21, 12:12:54
Reply #3

edredar

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I've cleaned and reuploaded the scene. Sorry, I didn't know that was a virus, thought it was some Max glitch.
Regarding UVWs and Subdivision. UVWs are not automatically generated, they are made by hand, so I don't think it is about UVW.
Subdivisions work! Thanks for this workaround. But why? Geometry isn't corrupted, quads only, vertices are welded etc. Does Corona work bad with relatively thin and long polygons?

2020-07-24, 16:59:55
Reply #4

a_bolog

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Try to ctrl+a all the vertices, and weld then with the option of 0.001 or something. Then autosmooth all the polygons.

Also, have you ever noticed this bug when you render-to-texture? https://forum.corona-renderer.com/index.php?topic=30202.0
« Last Edit: 2020-07-24, 17:10:46 by a_bolog »

2020-07-31, 13:16:52
Reply #5

edredar

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Nope, all vertices are already welded, and smoothing groups are the way they should be. Those were the things I've checked in the first place. Seems like long narrow polygons are the thing here.
Regarding your bug - Jeez no, I've hadn't encountered that bug. Maybe, that's because I don't bake textures themselves, I'm using Corona to generate lightmaps only. As for suggestions - seems like a real bug in renderer itself. Maybe, it has something to do with the virtual camera used to RTT (there is one, I guess). Or, if it was realtime rendering, I'd say it's definitely about anisotropic filtering or mipmaps. Anyway, I believe Corona Team knows better :)