New Corona Physical Material (PBR) playground!

[Corona_GK]

From the latest Corona Renderer 7 Daily Builds Changelog:

• Added new grounds up PBR material - CoronaPhysicalMaterial - Renamed CoronaMaterial to CoronaLegacyMaterial
  • There should be no change in existing maxscript which uses CoronaMaterial
• Fix of “No sockets could be bound!” DR failure
• Fixed memory leak when rendering hair

Download Link: Dropbox - Error - Simplify your life

CoronaPhysicalMaterial is now available, please give it a try and share your feedback with us.

How it works:
Simply create a new material > Corona > CoronaPhysicalMtl, the older version of CoronaMtl is now labeled as CoronaLegacyMtl.

CoronaPhysicalMtl consists of two modes-types that can be switched from the metalness rollout, Metal (conductor) and Non-metal (dielectric). Most of the basic parameters now change depending on the mode selected and the preferred material type. Various presets can be found in the material’s basic options rollout.

Since this is a physically based model, index or refraction-reflection is now limited to 3.0, reflection and refraction IOR are also connected into a single parameter (by default a highly refractive material, i.e. diamond will also have highly reflective surface if not rough). Metal materials don’t use IOR for reflection intensity, rather their reflectance strength is based on color, roughness value or applied map, do note that roughness or glossiness model that can be interchanged from the Advanced options rollout of the CoronaPhysicalMtl itself.

What else is new?
A ClearCoat layer is now included within the material, this can help coating your materials with a new layer that can have a different IOR reflection, separate bump, different roughness, and absorption color. A great example of this is a PVC Plastic coated with a resin layer or other types of coats. Comparison of CoronaLegacyMtl with no coating and CoronaPhysicalMtl with coating: CMTL vs PBR 5 | Corona Renderer

One more great addition is that of the Sheen layer which is responsible to represent an approximation of microfibers on cloth-surfaces like velvet or satin or other varying organic and rough surfaces. With a proper bump map it is now possible to emulate such cloth materials without the use of falloff, but by glossiness/roughness anisotropy and sheen layer alone.

Lastly, there has been a rearrangement of various UI elements to be significantly more accessible to the user, best examples of this are the addition of Bump control in the Base layer section along with a better restructuring of parameters.

Is this it?
Anisotropic refraction is now a thing ;).

Corona Physical-material can be used along with CoronaLayeredMtl, a comparison between CoronaLegacyMtl and CoronaPhysicalMtl: CMTL vs PBR 4 | Corona Renderer

Coating on refractive spheres, a comparison between CoronaLegacyMtl and CoronaPhysicalMtl: CMTL vs PBR 1 | Corona Renderer

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Credits for assets used in the tests (CC0 attribution license):
Butterfly, VirginiaTechUnivLibraries: Monarch Butterfly - Download Free 3D model by University Libraries at Virginia Tech (@VirginiaTechUnivLibraries) [3a5fc9a] - Sketchfab
HDRI: Peppermint Powerplant HDRI • Poly Haven

[Alex_87]

this looks amazing!

[scionik]

Just WOW. Let’s play with it. Thank you!

[juninholiveira]

Amazing! A question: The Corona Converter is already updated to convert to this new CoronaPhysicalMaterial? And what about the already existing Material Library? Any intentions to it?

[tom_grimes]

The converter is not updated yet, because the material is not finalized (we are waiting on feedback from everyone to see if there needs to be further changes ). Can’t start on the converter til the material is nicely locked and final, otherwise we’ll just be re-writing the converter constantly

[88qba88]

I’ve made some quick tests and I have a question about the visible brightness of new material.
Scene is made of 2 planes, 2 teapots and 2 spheres.
On part marked as NEW - new shader is applied, on part marked as OLD - Legacy Material is applied.

1 Corona Sun (size 1, value 1)
Environment - CoronaSky

Legacy Material settings:
Diffuse color: Corona Color R:180 G:180 B:180
Reflection: 1,0
Glossiness: Corona Color R:80 G:80 B:80

NEW: (same as above, switched from roughness to glossiness)
Mat settings:
Base Color: Corona Color R:180 G:180 B:180
Reflection: 1,0
Glossiness: Corona Color R:80 G:80 B:80
Non-metal

I can see that part with new material changes brightness quite hard depending on viewing angle. I believe the plane should be brighter when viewed towards the sun and darker in opposite direction?

Another issue seems to be visible when the camera is perpendicular to sun - I can see some changes in visible brightness of the plane from left to right.

Is that correct behavior?

Thanks

[Juraj_Talcik]

Nice :- )

[Bowcat]

Exciting!!!
Could anyone post a screenshot of the material UI in the material editor please?

[chris_widdowson]

@lupaz

[chris_widdowson]

So if we have to specify metalness (metal or non-metal) at the top of the material, which do you choose if both metal and non-metal surfaces are represented in a single texture set?

[mohammadreza_mohseni]

I am gonna have so much fun to test this daily build.

[romullus]

@cjwidd

So if we have to specify metalness (metal or non-metal) at the top of the material, which do you choose if both metal and non-metal surfaces are represented in a single texture set?

You should use layered material then. Same as with legacy material.

[tom_grimes]

@cjwidd

So if we have to specify metalness (metal or non-metal) at the top of the material, which do you choose if both metal and non-metal surfaces are represented in a single texture set?

There’s a map slot for metalness, if you want a material to vary metal to non-metal over the surface.

[chris_widdowson]

@TomG

@cjwidd

So if we have to specify metalness (metal or non-metal) at the top of the material, which do you choose if both metal and non-metal surfaces are represented in a single texture set?

There’s a map slot for metalness, if you want a material to vary metal to non-metal over the surface.

Nice, so between your response and Romullus’ it sounds like the functionality from the Legacy Material is preserved.

[agentdark45]

@bluebox

Am I correct to say that you guys implemented oren-nayar diffuse model ? This looks really really promissing !

Would like to know more about this for sure. The Arnold examples posted a while ago really benefited from the diffuse model.

Also, is there a guide for how to use legacy reflection and glossyness maps with the new PBR material?

Also, under what circumstances would you use the metalness/non-metal workflow? For example; semi-polished concrete, dark antique/tarnished bronze, polished marble, silk rugs, car paint e.t.c. I’m a bit confused as to where the cut off point is where materials have a reflective but also strong diffuse component. Or am I misunderstanding metalness?

[chris_widdowson]

I don’t think there is such a thing as ‘legacy reflection and glossyness maps’ in the context of the physical material(?)

[Ondra_1]

@cjwidd

So if we have to specify metalness (metal or non-metal) at the top of the material, which do you choose if both metal and non-metal surfaces are represented in a single texture set?

In that case you will set a metalness map, and the dropdown will become greyed out, signalling that it is no longer used. Both options for metal and non-metal material become unlocked.

[Ondra_1]

@agentdark45

Also, under what circumstances would you use the metalness/non-metal workflow? For example; semi-polished concrete, dark antique/tarnished bronze, polished marble, silk rugs, car paint e.t.c. I’m a bit confused as to where the cut off point is where materials have a reflective but also strong diffuse component. Or am I misunderstanding metalness?

metalness should be really used only for materials made of metal - so concrete, marble, silk are non-metal. Darkened bronze would be probably done with metalness map (metal bronze vs. non-metal “dirt”). Car paint is very complex and specific material, neither metal nor non-metal will represent it 100% physically, so I guess it would be possible to fake it with both

[bormax]

New material is really great! Thank you!

The Clearcoat layer is the thing I was missing for very long time, nice to get it now. Some idea came to my mind about it.
Now the Base bump affects the Clearcoat layer and Clearcoat bump gives possibility to Add bump to this layer. Would it be nice (if it’s possible) to have kinda lock between Base bump and Clearcoat bump in order to imitate the bumpy surface covered by the polished transparent layer of lacquer? Something like on attached picture where I’ve created the geometry of the covering layer and assigned different material to the inner and covering surfaces.
According to this idea if the Lock is active Base bump affects the Coatlayer, if it’s unlocked only Clearcoat layer’s bump affects the Coat layer.

[Corona_GK]

@88qba88

I’ve made some quick tests and I have a question about the visible brightness of new material.
Scene is made of 2 planes, 2 teapots and 2 spheres.
On part marked as NEW - new shader is applied, on part marked as OLD - Legacy Material is applied.

1 Corona Sun (size 1, value 1)
Environment - CoronaSky

Legacy Material settings:
Diffuse color: Corona Color R:180 G:180 B:180
Reflection: 1,0
Glossiness: Corona Color R:80 G:80 B:80

NEW: (same as above, switched from roughness to glossiness)
Mat settings:
Base Color: Corona Color R:180 G:180 B:180
Reflection: 1,0
Glossiness: Corona Color R:80 G:80 B:80
Non-metal

I can see that part with new material changes brightness quite hard depending on viewing angle. I believe the plane should be brighter when viewed towards the sun and darker in opposite direction?

Another issue seems to be visible when the camera is perpendicular to sun - I can see some changes in visible brightness of the plane from left to right.

Is that correct behavior?

Thanks

That is indeed expected as the new diffuse model is somewhat retro-reflective at low glossiness.