Author Topic: Triplanar- and displacement mapping inconsistency  (Read 1070 times)

2018-07-24, 11:57:34
Reply #15

Fluss

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Of course it should, just make sure that there is bug report about that. If not, then please create separate report, so it won't be lost.

It just worked on my simple test.... Looks like the issue is on the layered material side. Will test it further and make an appropriate bug report (if needed as i've just seen there are some existing report on layered materials with displacement). So nothing correlated to your issue, forget what I said :)

2018-07-24, 13:06:20
Reply #16

maru

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Is there any consensus about this issue? Will it be addressed? I'm creating my own material library and to my dismay i found that i can't use triplanar with materials that have displacement :[
I don't think that's really "fixable" because of two things:
1) Triplanar is by definition supposed to work outside of any UVW restrictions
2) If we would "fix" that, then people would complain that they are displacing some landscape, and then triplanar is not working how they would expect :)

2018-07-24, 13:57:28
Reply #17

romullus

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1) Triplanar is by definition supposed to work outside of any UVW restrictions

I don't know technical details, but isn't this just a matter of order of operations? If displacement would be applied last instead of first, then it should give better result.

2) If we would "fix" that, then people would complain that they are displacing some landscape, and then triplanar is not working how they would expect :)

Trying to thing logically, how many cases there is, where current behaviour makes conventional materials unusable, versus number of cases where somebody wants to use triplanar for displacing the mountains? I think that Juraj and others already threw in some good ideas, how this can be improved. I think that this definitely should be fixed.
I'm not Corona Team member! Everything i say, is my personal opinion only. Render Legion does not endorse my words nor actions.

2018-07-24, 14:35:45
Reply #18

Fluss

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Possible solution to this would be that material displacement always acts on existing UVWs, as expected, not as shown in this thread, and geometry displacement modifier being given option to take precedence.

I think both displacement methods should behave the same way otherwise it will introduce some confusion. Consistency is the key. I'd rather have an option for displacement order in the triplanar map itself. That way, it would also allow mixing both methods in a single material (even if I don't see any use case of this right now, anyway it's there). Kind of a "compute before displacement" checkbox, unthicked by default so the current behavior is not affected.
« Last Edit: 2018-07-24, 15:23:05 by Fluss »

2018-07-24, 15:41:18
Reply #19

maru

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2019-03-14, 11:16:59
Reply #20

maru

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The official answer here is that currently the Triplanar map works as expected and we are not going to change it. The object is displaced first, and then the Triplanar map is projected from all axes. This means that Triplanar mapping should be used for uniform details such as scratches or noises, and for defined patterns running in some specific direction it is best to use classic UVW mapping. More details here: https://corona-renderer.com/forum/index.php?topic=20616.0

We are of course open to further discussion.

2019-03-14, 11:27:41
Reply #21

romullus

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Well, that's a second sad news i heard today. It looks like my day has started on the wrong foot :/
I'm not Corona Team member! Everything i say, is my personal opinion only. Render Legion does not endorse my words nor actions.

2019-03-14, 17:12:25
Reply #22

PROH

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Hi Maru. That is how one would expect displacement to work when using a displacement modifier. But inside a material, I would certainly expect all maps to "follow" each other - meaning displacement should be added last! This is bad!!