Author Topic: UVW Randomizer Issue  (Read 3962 times)

2022-09-26, 16:42:10
Reply #15

dj_buckley

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That's correct, when you're rotating normal map, it's the same as if you'd rotate mesh normals themselves. No doubt this will give you all sorts of weird illusions. It is best to leave W rotation alone and stick to U, V randomization only when normal maps are involved.

Wow, this is kinda mind-blowing to me. Obvious now that I think about it

haha i had this same realisation when I ran that test today

2022-09-26, 16:49:37
Reply #16

romullus

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I often randomise the rotation of wood but with a Step value of 180.

Good point, but i think that wouldn't mess normal map, since XYZ coordinates would still match UVW.
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2022-09-26, 16:53:54
Reply #17

dj_buckley

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And to be fair, if it did, it would hardly be noticeable as the wood grains I use aren't so dramatic in terms of 'bump' amount.

2022-09-28, 10:01:04
Reply #18

DPS

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I often randomise the rotation of wood but with a Step value of 180.

Good point, but i think that wouldn't mess normal map, since XYZ coordinates would still match UVW.

Yeah I don't see the problem with randomizing the normal map in conjunction with the other maps.

Still a pain in the but that displacement doesn't line up properly.
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2023-04-14, 20:16:41
Reply #19

romullus

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Just to update things - apparently the solution to the issue is to keep correct order of nodes. Corona normal node must go before UVW randomizer, which must go before triplanar. More information about this can be found at Chaos support portal: https://support.chaos.com/hc/en-us/articles/13800753963537
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2023-04-17, 17:27:27
Reply #20

maru

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If you plug a normal map into the randomizer - the randomizer knows that this is a normal map and it should be treated in a special way (if you rotate a convex thing - it will remain convex)

if you plug a bitmap into the randomizer and then into a normal node - then Corona will take the result of the randomization (the normal map rotated and transformed the way you set it) and will then interpret this as a regular normal map - so whatever is red will be treated as red, whatever is green - as green, and whatever is blue - as blue) - this can result in "flipped normals" effect

the different orders of bitmap > normal > randomizer > triplanar will produce different effects - you may sometimes want to use the "incorrect" order if it makes sense in your specific case
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