Author Topic: (Daily Build 2020-02-27 & v5) - Bump Map textures unreliable at different res.  (Read 895 times)

2020-03-27, 17:36:20

Nejc Kilar

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Hello! :)

So this is a big one and imho should be at the top of the priority list because it makes bump mapping unusable in production workflows. Imho it is a big oversight that this is in the stable release :\

Anyway, the bump map literally renders differently when rendered in 1k resolution compared to say 6k resolution. The way that the bump effect looks is quite noticeably different.

I'm attaching a quick comparison screenshot.

OS: Windows 10
« Last Edit: 2020-03-27, 17:47:26 by Nejc Kilar »

2020-03-30, 15:44:57
Reply #1

beanzvision

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Hey Nejc,

Are you able to supply a sample scene at all? I've tried to recreate it but I'm not having much luck. Cheers ;)
https://corona-renderer.com/upload

2020-03-31, 11:59:38
Reply #2

Nejc Kilar

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Hey Bengamin,

Yeah, I'll see what I can do to get you the scene. From what I can tell so far I can easily reproduce the issue so I'll try to get you the scene in the upcoming days.

2020-03-31, 13:19:39
Reply #3

beanzvision

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2020-03-31, 14:48:31
Reply #4

burnin

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Got a scene here and it doesn't seem to differ that much or I'm just going slightly blind...
but might also be the CPU(?) Done on AMD TR 1950X.

I also found that the shading issue (Artefacts when using background and corona sky object) can be replicated even with just using an area light on capsule or other capped & filleted objects (on edges where this "patches" join).

More bumpy problems might occur with high reflective, metals and anisotropic shading. As if each pixel gets bumped separately (appears as a gap between pixels). But I need to find a definite way to reproduce it (unless it's been fixed - am using v6 daily1 here)

Scene file: CRN_BumpAnisoShade-Bugz.7z | 167.9 MB @ MEGA // all textures CC-0



2020-04-20, 11:29:05
Reply #5

djstevanovic

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I tried scene above and got i think ok results, cinema r19 & corona v5 hotfix2



2020-05-18, 23:35:49
Reply #6

Nejc Kilar

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Just to update this thread, it could be that this issue is present mostly on 2 socket systems - high end Xeon workstations.

There is a lot in common with this particular thread, at least when it comes to speed hits - https://corona-renderer.com/forum/index.php?topic=24238.0

So right now not only bump mapping doesn't work properly when rendering "big" it also incurs a significant speed penalty when not using CBitmaps which as we all know can't be scaled. :(

2020-05-19, 20:09:45
Reply #7

Nejc Kilar

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After playing around with it a bit more I can definitely reproduce the issue every single time if one uses the Layer -> Transform command to scale the bump bitmap. The resulting bump map effect will look broken at higher resolution. Using the same exact procedure and rendering at 1/3rd of the resolution will look great though.

For the above I'm specifically comparing 6k vs 2k images.

All that said, even if I render a single map in 6k and compare it to 2k there are differences in the way bump is applied. It is less pronounced but it is there and it can look quite a bit different. I've tested it with and without CBitmaps but ultimately this particular point probably comes down to texture filtering that was already reported before.

So from my quick re-testing here it seems like yeah, we currently don't have the ability to scale bump maps in Corona for Cinema 4D - the transform is buggy (as noted in the first paragraph) and the projector doesn't work / isn't supported. This is a major problem for production work :\