Author Topic: New Corona Physical Material (PBR) playground!  (Read 42961 times)

2021-08-09, 20:31:33
Reply #240

romullus

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Unlike normal maps, bump maps don't have single correct strength value. Strength of 0.01 can be equally as correct as strength 1, it all depends on your texture and the look you are after. I didn't test it myself, but it's pretty unlikely that devs decided to change bump strength for the new PBR material.
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2021-08-10, 11:27:55
Reply #241

Bornix

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How about bump in new PBR materials? As I remember in many tutorials there was a rule that correct bump is 0-0,1. 1 is unnatural and too strong in legacy material. Is this "rule" still correct?

I would really like an official source for this, if possible^

I'm also starting to think that I worked at the wrong place where I was taught the wrong methods and habits.

2021-08-10, 14:48:56
Reply #242

marchik

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I was looking through the built-in library of materials today and I had a question, earlier, before the introduction of the physical shader, we had the opportunity to enable volumetric absorption with scattering after the light passes through the translucent outer shell, this is the pattern for the "Marble White SSS" material.
How to set up such materials now (grape shader, for example), because to enable translucency, we need to check the "thin shell" checkbox, which will automatically disable the ability to adjust volumetric absorption, and so on.

2021-08-11, 13:50:41
Reply #243

Horse

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Where i can find library with new PBR materials... does it exist at all ?

2021-08-11, 13:54:48
Reply #244

TomG

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Where i can find library with new PBR materials... does it exist at all ?

The Corona Material Library was updated so that some are using the new Physical Material (the ones that are most affected by the change - there wasn't time to convert them all, as mentioned in the blog:
"We’ve also converted some of the previously existing materials to use the new Physical Material in place of the Legacy Material, with the addition of things such as sheen to fabrics, etc. These are the Carpets, Flooring, Concrete, and Ceramic Tiles categories"

https://blog.corona-renderer.com/corona-renderer-7-for-3ds-max-released/

2021-08-12, 11:29:54
Reply #245

GeorgeK

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I was looking through the built-in library of materials today and I had a question, earlier, before the introduction of the physical shader, we had the opportunity to enable volumetric absorption with scattering after the light passes through the translucent outer shell, this is the pattern for the "Marble White SSS" material.
How to set up such materials now (grape shader, for example), because to enable translucency, we need to check the "thin shell" checkbox, which will automatically disable the ability to adjust volumetric absorption, and so on.

I am afraid that's not possible with Coronaphysical mtl, due to the fact that when using ThinShell, refraction is replaced by opacity, and subsurface scattering is replaced by diffuse and translucency.

For marble or porcelain, I would suggest using Volumetric or Subsurface scattering (with the latter being faster to set up and to render). In a case where you still want to employ translucency + volumetrics, you will have to resort to using Coronalegacy mtl.
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2021-08-16, 15:22:31
Reply #246

Bornix

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Hi!

It is impossible to use CoronaShadowCatcherMtl with new Physical Glass Material. There is only one solution to use old legacy material and check Thin (no refraction) option. Will you ever improve Shadowcatcher in future?

2021-08-17, 11:06:40
Reply #247

GeorgeK

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Hi!

It is impossible to use CoronaShadowCatcherMtl with new Physical Glass Material. There is only one solution to use old legacy material and check Thin (no refraction) option. Will you ever improve Shadowcatcher in future?

Hi, can you please clarify what's the issue, please share some reproduction steps as to why is not working for you.

Thanks,
For solutions, troubleshooting, ticket requests please visit - [link]

2021-08-17, 19:33:16
Reply #248

cjwidd

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Dumb question, but I just want to clarify: 'Base IOR' in CoronaPhysicalMtl is NOT the same as 'Fresnel IOR' in CoronaLegacyMtl, correct?

Also, it's often good practice to pass a reflective metal into a Rayswitch with a pure black materia in the GI slot. To create the pure black material, I would zero out the reflection, but because in the IOR model of CoronaPhysicalMtl there is no reflection spinner, do we just zero out IOR instead to replicate that effect?
« Last Edit: 2021-08-17, 19:58:08 by cjwidd »

2021-08-17, 20:03:17
Reply #249

TomG

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Depends on what you mean by the same:
- Yes it's the same, it defines the IOR of the reflections. If you are looking for the equivalent to "Fresnel IOR", then this is the one.
- No it's not the same, as it also defines the IOR of refraction (because any real world material only has one IOR affecting both reflection and refraction, not two IORs like the old Legacy Material)
- No it's not the same, as it only goes up to 3 (because real world non-metals don't have an IOR of more than 3, even though the Legacy let you use up to 999, and now the Physical Material has Metal or non-Metal modes)
- No it's not the same as you can't set it for metals, it's preset, unlike in the old Legacy
- And overall in the material, it's not quite the same as there is a Clearcoat layer with its own IOR, which didn't exist in the Legacy Material, so the overall reflectivity of your object may be different than just the Base IOR / Legacy IOR)

Set IOR to 1 for no reflections, yep. You could set Roughness to 1 too but I think that's redundant when IOR is 1. You wouldn't zero out IOR because it doesn't go below 1 :)

2021-08-19, 11:24:06
Reply #250

Bornix

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Hi!

It is impossible to use CoronaShadowCatcherMtl with new Physical Glass Material. There is only one solution to use old legacy material and check Thin (no refraction) option. Will you ever improve Shadowcatcher in future?

Hi, can you please clarify what's the issue, please share some reproduction steps as to why is not working for you.

Thanks,

I made simple scene look:

It is impossible to made glass transparent in alpha channel with new physical materials. Shadowcatcher is not working with refraction even with thin shell option set on. Is there any chance that Shadowcatcher would work with refraction in future?
« Last Edit: 2021-08-19, 11:32:33 by Bornix »

2021-08-19, 11:39:01
Reply #251

burnin

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Fundamental Physics
Fresnel prevents any surface to be 100% transparent.

PS
Use Legacy Material.

2021-08-19, 12:34:35
Reply #252

GeorgeK

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Thanks for the example, I am reporting it as I am unaware if it's expected or not. Regards,

(Report ID=CRMAX-910)

For solutions, troubleshooting, ticket requests please visit - [link]

2021-08-19, 15:11:44
Reply #253

cjwidd

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off-topic: will the recent webinar be posted to the Corona Renderer YouTube channel?

2021-08-19, 15:25:39
Reply #254

TomG

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off-topic: will the recent webinar be posted to the Corona Renderer YouTube channel?

Yep, and that should be later today if all goes well :)