Author Topic: New Corona Physical Material (PBR) playground!  (Read 84570 times)

2021-01-19, 11:20:40
Reply #75

Mohammadreza Mohseni

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I hope the name of CoronaLegacyMtl class would go back to CoronaMtl class which would be really easier to find because of the years of habit and since it completely distinguishes itself from the CoronaPhysicalMtl class I did not grasp the need for changing the class name.

ps: I know it works with both in maxscript because of the compatibility and we have two class for one single thing but I mean the name that shows in the material editor
« Last Edit: 2021-01-19, 11:24:22 by Mohammadreza Mohseni »

2021-01-19, 11:30:19
Reply #76

marchik

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There is one more thing, due to the connection between roughness of reflections and roughness of refractions, it became virtually impossible to add, for example, fingerprints to the glass surface, because even the stained glass remains with 0 roughness, at first I thought that this could be solved with clearcoat but my attempts did not lead to anything good. It seems a little strange to me that when adding new functions, old ones break) and ofc the same concerns translucency color map, which in some cases just necessary
I hope you wont delete the legacy shader because sometimes some "fakes" lead to good results or maybe it will be a good idea to add "expert" mode in our new physical material which will break those "physicall correct connections"

I haven't tried it myself yet but I suspect that a potential workflow for this could revolve around having the glass be the base in a Corona Layered material while the fingerprints come on top with a mask using it's own separate material.

no doubt this can be solved, but what is the point in this innovation if it does not make working with the render engine easier?
In this case, we may not use maps for roughness or base color at all, but simply mix the necessary materials by masks: D: D: D

2021-01-21, 10:37:56
Reply #77

cjwidd

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it became virtually impossible to add, for example, fingerprints to the glass surface

Why isn't this solved by just passing a roughness / glossiness map into the roughness / glossiness channel of a refractive (glass) material? I would presume that would be sufficient for ~90% of cases - maybe even for the remaining edges cases in which a close-up is required(?)

2021-01-21, 11:12:34
Reply #78

marchik

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it became virtually impossible to add, for example, fingerprints to the glass surface

Why isn't this solved by just passing a roughness / glossiness map into the roughness / glossiness channel of a refractive (glass) material? I would presume that would be sufficient for ~90% of cases - maybe even for the remaining edges cases in which a close-up is required(?)

because even a refraction glossiness of 0.99 results in blurry unwanted results for me) ofc it is not "critical" but personal for me, i want to have an option to unlink refl/refr roughness

2021-01-21, 14:36:49
Reply #79

GeorgeK

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it became virtually impossible to add, for example, fingerprints to the glass surface

Why isn't this solved by just passing a roughness / glossiness map into the roughness / glossiness channel of a refractive (glass) material? I would presume that would be sufficient for ~90% of cases - maybe even for the remaining edges cases in which a close-up is required(?)

because even a refraction glossiness of 0.99 results in blurry unwanted results for me) ofc it is not "critical" but personal for me, i want to have an option to unlink refl/refr roughness

Working with the coat layer for the fingerprints wouldn't solve your issue?
« Last Edit: 2021-01-22, 18:28:00 by GeorgeK »
George Karampelas | chaos-corona.com
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2021-01-21, 20:24:33
Reply #80

marchik

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Working with the coat layer for the fingerprints wouldn't work for your case?

logically, this approach should work, but I still cannot get it to produce a similar result. It would be logical to set the required roughness value for the coat layer and apply it using a contrast mask, but as a result, the picture is more noisy and the pattern of smudges does not turn out to be as clear, of course you can always tweak  this to death, but it seems to me that this should not work like that.

2021-01-22, 10:41:01
Reply #81

pokoy

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I think the map should go into clearcoat roughness (inverted), not clearcoat amount. Clearcoat amount needs to be >0 then, of course.

2021-01-22, 15:24:20
Reply #82

cjwidd

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2021-01-22, 19:43:01
Reply #83

marchik

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I think the map should go into clearcoat roughness (inverted), not clearcoat amount. Clearcoat amount needs to be >0 then, of course.

Nope) you can try it yourself) as I said, a workaround can of course be found, but I cannot understand the ultimate purpose of this simplification if it only complicates the task.
PS and finally, if this is a "physically correct" shader, why should I add a layer of transparent glossy varnish to the glass if it is not there?

2021-01-22, 21:19:02
Reply #84

romullus

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PS and finally, if this is a "physically correct" shader, why should I add a layer of transparent glossy varnish to the glass if it is not there?

Technically fingerprint marks are not the part of the glass, it's a layer of grease and dirt on top of the glass. Maybe using clearcoat is not the best solution, but physically it's more correct than making fingerprints as a property of the glass.
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2021-01-22, 22:42:31
Reply #85

pokoy

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Yes, some things are now easier to achieve by using LayerMtl. I don't like it myself that much but there's hardly a way to make everything easier with the new material.
The thing is that LayerMtl needs some work now too - displacement, bump, some properties only being used when in base material etc. The new PBR material certainly implies a few challenges here and there.

2021-01-23, 10:30:50
Reply #86

marchik

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PS and finally, if this is a "physically correct" shader, why should I add a layer of transparent glossy varnish to the glass if it is not there?

Technically fingerprint marks are not the part of the glass, it's a layer of grease and dirt on top of the glass. Maybe using clearcoat is not the best solution, but physically it's more correct than making fingerprints as a property of the glass.
Absolutely, but i'm talking about using clearcoat roughness parameter instead of clearcoat amount
I think the map should go into clearcoat roughness (inverted), not clearcoat amount. Clearcoat amount needs to be >0 then, of course.



in this case it is absolutely obvious that the glass surface without fingerprints is not covered with any clearcoat at all

2021-01-23, 12:21:58
Reply #87

GeorgeK

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PS and finally, if this is a "physically correct" shader, why should I add a layer of transparent glossy varnish to the glass if it is not there?

Technically fingerprint marks are not the part of the glass, it's a layer of grease and dirt on top of the glass. Maybe using clearcoat is not the best solution, but physically it's more correct than making fingerprints as a property of the glass.
Absolutely, but i'm talking about using clearcoat roughness parameter instead of clearcoat amount
I think the map should go into clearcoat roughness (inverted), not clearcoat amount. Clearcoat amount needs to be >0 then, of course.



in this case it is absolutely obvious that the glass surface without fingerprints is not covered with any clearcoat at all

Some differences in roughness are to be expected, the underlying models in Physical material are different than in the legacy material. Diffuse reflection is different based on base glossiness/roughness, reflection is normalized (scaled in order to not lose energy) differently to be more physically plausible.

Comparison 1, HDRI lighting: https://corona-renderer.com/comparer/NugVgk
Comparison 2, two light sources: https://corona-renderer.com/comparer/Uw9dpN

In my opinion, I find the physical model to be more accurate, but I can see how this might need some effort into being get used to, as always if a lot of voices raise concern we will forward your criticism to the devs for further consideration.

(Report ID=CRMAX-71)
George Karampelas | chaos-corona.com
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2021-01-23, 13:34:34
Reply #88

marchik

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Some differences in roughness are to be expected, the underlying models in Physical material are different than in the legacy material. Diffuse reflection is different based on base glossiness/roughness, reflection is normalized (scaled in order to not lose energy) differently to be more physically plausible.

Comparison 1, HDRI lighting: https://corona-renderer.com/comparer/NugVgk
Comparison 2, two light sources: https://corona-renderer.com/comparer/Uw9dpN

In my opinion, I find the physical model to be more accurate, but I can see how this might need some effort into being get used to, as always if a lot of voices raise concern we will forward your criticism to the devs for further consideration.

(Report ID=CRMAX-71)

Thank you very much, this is more likely not a criticism, I just try to use a new shader in my daily work and check as many controversial points and difficulties in use as possible, and accordingly I am writing about the results here.

I would also like to know the opinion of the dev team about the implementation of bump "replacement" in the clearcoat  layer as we mentioned before)
the item about the implementation of the new shader in the roadmap was fully checked yesterday and it makes me worried: D

2021-01-28, 16:15:01
Reply #89

boston.george

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Stupid question:

Where is reflection slot?