New Corona Physical Material (PBR) playground!

[romullus]

@marchik

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.

[pokoy_1]

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.

[marchik]

@romullus

@marchik

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

@pokoy

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

[Corona_GK]

@marchik

@romullus

@marchik

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

@pokoy

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: Legacy Glossiness vs PBR Coat Glossiness | Corona Renderer
Comparison 2, two light sources: Legacy Glossiness vs PBR Coat Glossiness 2 | Corona Renderer

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)

[marchik]

@GeorgeK

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: Legacy Glossiness vs PBR Coat Glossiness | Corona Renderer
Comparison 2, two light sources: Legacy Glossiness vs PBR Coat Glossiness 2 | Corona Renderer

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

[giorgiodeleo]

Stupid question:

Where is reflection slot?

[enrico.lapponi]

@boston.george

Stupid question:

Where is reflection slot?

I think the slot we knew as Reflection now it’s been incorporated in the Base layer under the Color option, which makes sense because in reality the base color and specular reflection are one thing, in cgi they are separated for artistic purposes, at least this is how I understand it. Also in the tool tip there is a simple explanation.

[N2graf]

@maru

@n2graf

For metallic materials that accumulate a thin layer of dust…

The issue is that metal and dust are two completely different materials. Layered Mtl would be definitely preferred here.
Maybe you could also use the built in Sheen layer? (you can specify its color, amount, and roughness so it’s a bit like a layer of non-metal).

Yes they are completely different, but In the real world there are no pure metals, within seconds of leaving the furnace, they begin to oxidize in a very thin and superficial layer that itself serves as a shield so that the oxidation continues to advance inwards. In this way there will always be a certain mixture of non-metal in metallic materials. Having to always use multimaterial to solve this is very laborious and does not make sense. It is much more practical to be able to lower the amount of non-metal with a spinner and attach a slot for the diffuse color that is operative only when we activate the spinner.
Sheenlayer with roughtness at 1 does not work well. As you can see in the metal gold image, the blue sheenlayer is increased in the tangential parts when a diffuse one should mix equally in all areas.

[Anatoly_1]

I suggest that you need to add a very understandable and detailed chapter on helpdek site, explaining this “new” material approach with comparison to traditional one, and how one should migrate to it, filled with examples and tutorials.

I believe that it would take some effort for a lot of users, who used to classic approach, to start using this new one with the same ease. Currently I can imagine exactly what map should be in reflect, refract, diffuse, translucency, e.t.c. slot, to make material look as intended. This is not the case with PBR material, and you can see it by the questions above, and I believe that here is the progressive part of your audience.

Maybe it would be a good idea to add some script that converts traditional materials to Physical, converting and placing all maps correctly, to achieve correct result. Or may be some map node that would take a traditional diffuse, reflect, refract, translucency and other maps on the input, and generate correct output maps required for PBR, like roughness, metalness and others. This might help with asset migration and migration in general. One could see how new PBR maps should look like, to achieve the same (or close to the same) result as with the classic approach.

Thank you. Hope this make sense.

[Mantaskava]

@Anatoly

I suggest that you need to add a very understandable and detailed chapter on helpdek site, explaining this “new” material approach with comparison to traditional one, and how one should migrate to it, filled with examples and tutorials.

Totally agree with Anatoly on this one.
I want to see various examples of various materials converted correctly from legacy to new PBR material (or in other words, in a way developer intended). All with clear explanations, like what bitmap goes where and why.
I don’t want to spend another weak experimenting and guessing if it’s the most efficient/correct way of doing this or that or not.
Hope you’ll consider this and make it real.

Thanks

[Corona_GK]

@mantaskava

@Anatoly

I suggest that you need to add a very understandable and detailed chapter on helpdek site, explaining this “new” material approach with comparison to traditional one, and how one should migrate to it, filled with examples and tutorials.

Totally agree with Anatoly on this one.
I want to see various examples of various materials converted correctly from legacy to new PBR material (or in other words, in a way developer intended). All with clear explanations, like what bitmap goes where and why.
I don’t want to spend another weak experimenting and guessing if it’s the most efficient/correct way of doing this or that or not.
Hope you’ll consider this and make it real.

Thanks

Not just considering it, already doing it ;).

We are also looking into a viable and efficient conversion method between a legacy material and a physical one.

Thanks for your feedback.

[Corona_GK]

Hi all,

Just so to clarify some things with regards to the IOR/Specular Mapping request.

• The entire idea behind it is to have an IOR node that internally reverts specular input (or gives the option to do so) and also translates the RGB bitmap values of 0-1 to a numerical IOR indicator within the texmap node?

Would it be possible to offer a practical example of this, I am assuming that this includes a workflow along with other software, if so yes can you please specify which?

Thanks.

(Report ID=CRMAX-168)

[celly00]

How set are the properties of the material? I don’t have the opportunity to install the beta, but I would like to prepare some of my scripts for when it goes live. Could someone so kindly post the properties of the material class? Can be done by typing in Show CoronaPhysicalMaterial in the listener (assuming the class is named as such, otherwise Show $.material with an object selected that has the material applied should work, iirc)

[maru]

@niljut

How set are the properties of the material? I don’t have the opportunity to install the beta, but I would like to prepare some of my scripts for when it goes live. Could someone so kindly post the properties of the material class? Can be done by typing in Show CoronaPhysicalMaterial in the listener (assuming the class is named as such, otherwise Show $.material with an object selected that has the material applied should work, iirc)

I think it would be best to wait for the final version, because the current ui/properties can still change.

[Fluss01]

wow didn’t check the forum in a while! That new shader looks sexy! I’ll have to give it a try

[marchik]

@GeorgeK

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: Legacy Glossiness vs PBR Coat Glossiness | Corona Renderer
Comparison 2, two light sources: Legacy Glossiness vs PBR Coat Glossiness 2 | Corona Renderer

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)

with regard to the results, how were they achieved in this case? which parameter was mapped? clearcoat amount or clearcoat roughness?

And in addition, I may be wrong, but it seems to me that the format of the normal map has changed for the new material, is it so?

[Corona_GK]

@marchik

@GeorgeK

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: Legacy Glossiness vs PBR Coat Glossiness | Corona Renderer
Comparison 2, two light sources: Legacy Glossiness vs PBR Coat Glossiness 2 | Corona Renderer

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)

with regard to the results, how were they achieved in this case? which parameter was mapped? clearcoat amount or clearcoat roughness?

And in addition, I may be wrong, but it seems to me that the format of the normal map has changed for the new material, is it so?

The above examples were made with clearcoat gloss for the CoronaPhysicalMtl and reflection.gloss for the CoronaLegacyMtl, both materials shared the same maps in all slots and bump.

[Fluss01]

So we do not have control over the main specular lobe anymore?

[Mvskokvl]

Could you be more specific.
As I see it’s not separated anymore but simply optimized by it being connected, dependent… as is in real world.

[Fluss01]

Yes, it’s great when everything behaves physically but it’s also great to keep control when we need to, for artistic or whatever reasons. Hope we at least can access this through additional params.