New beta available: PBR, microfacets, Disney, Fresnel and tutti quanti

Philemo_Carrara

I've started a new plugin that allows import "as-is" of PBR textures (albedo, roughness/glossiness, Ambient occlusion and metallic) such as the ones produced by Substance.

So far, it's done for non-metallic materials (dielectric in PBR jargon).

To do that, I have implemented the Disney Principle BSDR as a lighting model. I've choosen it because it (or a modified version of it) is widely implemented (Blender/cycle, Appleseed, Renderman and many other included countless game engines). So, it was just time Carrara got itsown version :-). You can see here the Renderman documentation on this model (it's the best one I've found so far). On top of PBR, Disney Principle add (a not convincing) subsurface, anisotropy, sheen for cloth, glossy clearcoat.

 

 

 

 

TangoAlpha

Sounds interesting.

Philemo_Carrara

My test sequence starts an organic shape and a flat one in Carrara content 3 points lights preset (a difficult one for a lighting model).

The four textures have been applied "as-is" (no tweaking)

The textures have been downloaded from 3 sites:

• Textures.com
• FreePBR.com
• 3d-wolf.com

 

Diomede

Philemo, you are amazing.

WendyLuvsCatz

sounds awesome 

I wonder how well the Octane plugin would convert them?

magaremoto

looks great, but why don't you use a HDR image? It should highlight the goods and the bads of each one

UnifiedBrain

Philemo, you know I love your work.  But can you explain this in simpler terms for newer users (like myself)?

Philemo_Carrara

 

@TangoAlpha Actually, I think it is :-)

@Diomede Thank you for your appreciation

@th3Digit Thanks Wendy. Roughness maps load perfectly in Octane. If your question is about automatic conversion, I'm not so sure.

@magaremoto I'm not sure to understand the question. What do you mean by "using an HDR"?

@UnifiedBrain I'm not sure I'm able to explain it clearly, but you'll find a lot of information in this guide from Marmoset or this one from unreal engine

UnifiedBrain

Philemo said:

@UnifiedBrain I'm not sure I'm able to explain it clearly, but you'll find a lot of information in this guide from Marmoset or this one from unreal engine

I'm not looking for a technical explanation.  I just want to know how I would use it in a Carrara workflow.  That's my frame of reference.

And is it for Carrara, or Octane?

If I have to wait and see it in action until I grasp it, that's fine.  Like I said, I deeply appreciate your skills.

 

Bunyip02

Looks great !!!!

Philemo_Carrara

UnifiedBrain said:

I'm not looking for a technical explanation.  I just want to know how I would use it in a Carrara workflow.  That's my frame of reference.

And is it for Carrara, or Octane?

It's for Carrara.

It's fully integrated in Carrara:

On your multi-channel shader, choose a PBR lighting model:

It will create a new level with your multi channel as the first shader :

Usually, PBR texture sets come with at least 4 files:

• Albedo (or base color)
• Glossiness or roughness map
• normal map
• ambient occlusion map

Albedo

Load in color channel of your multi channel shader

Specular

PBR model accepts value ranging usually from 15% to 40% depending on the material IOR.

20% is usually a good start. Goes into the Highlight slot

Glossiness/roughness map

It goes into shininess slot.

Glossiness and roughness map are two side of the same notion. a Roughess map has value 0 for very smooth and 1 for very rough. A glossiness map is just the opposite (0 for rough, 1 for smooth). So, if you have a roughness map, hust tick the "invert color" tick box in the texture map

Ambient occlusion

In the ambient occlusion slot of the lighting model

And that's all for the basis.

 

UnifiedBrain

Wow, thanks!  That was what I needed to start to understand.  Your top shader dropdown menu is a lot more robust than mine. :) 

I'm guessing that this plugin will allow Carrara users to load a greater variety of textures, and that these textures will have a different (more realistic) "look."  I saw your examples above, but it is hard to evaluate what is different without direct comparisons in Carrara.  Are direct comparisons even possible?

I think that Magaremoto was wondering why you were using a three point light setup for evaluation, rather that using an HDRI.

Your G'MIC plugin changed the way that I use Carrara.  Hope this will have a similar positive impact.

Philemo_Carrara

I'm not sure direct comparaisons are possible because Carrara cannot interpret correctly the roughness map.

The idea is indeed to give an easy access to a wider range of resources. PBR being the new standard for materials, more and more providers are moving to PBR. As for having a more "realistic look", it depends. The Carrara render engine is still the same and one shouldn't wait for miracles :-). But, if PBR materials are good, there should be an improvement.

Now, for the three points light, it's because, in Carrara, lighting models respond only to true lights (bulb, spot, distant, area, whatever) and not to sky light. It's the way Carrara works and HDRI or Sky light are in the global illumination part of the shader. That's why rendering a scene (whatever the material) with no light except sky light will give a flat render, without highlights or shadows.

The only way a PBR material will react to environment (sky light or HDRI) is through reflection (ie metallic component) which I haven't implemented yet. A classic workaround is to create a light dome (Tim Payne has that for skies). I'm working on an other plugin that creates a light dome from an HDRI image, but it's not yet ready.

UnifiedBrain

Very clear explanations, thanks for taking the time!

chickenman

Philemo,

This is wonderful news thank you.

Do you know if it will be able to take the IRAY PBR materials that Studio is using in order to utilize them?

I wonder how it will look with the LuxCore implementation of PBR?

magaremoto

for the roughness did you take a look at the Schlik formula? https://en.wikipedia.org/wiki/Schlick's_approximation

magaremoto

this is how blender has introduced the disney shader into release 2.79: https://docs.blender.org/manual/en/dev/render/cycles/nodes/types/shaders/principled.html?highlight=principles

I hope it may help

3drendero

Thanks for the update Philemo.

Is a beta version planned?

Easier to setup some free shader packs in time for the full release...

Philemo_Carrara

chickenman said:

Philemo,

This is wonderful news thank you.

Do you know if it will be able to take the IRAY PBR materials that Studio is using in order to utilize them?

I wonder how it will look with the LuxCore implementation of PBR?

I don't know. I had a look in my Daz library if I could find IRay PBR, but I didn't find any (but, in the other hand, as I don't buy anything above genesis 2 from Daz, that may explain why). I you know of a PBR shader provided free with Studio, it may help.

Philemo_Carrara

magaremoto said:

for the roughness did you take a look at the Schlik formula? https://en.wikipedia.org/wiki/Schlick's_approximation

Yes, it's the one I'm using.

magaremoto said:

this is how blender has introduced the disney shader into release 2.79: https://docs.blender.org/manual/en/dev/render/cycles/nodes/types/shaders/principled.html?highlight=principles

I hope it may help

Thank you. Yes, it does, both for testing ideas and documentation.

Philemo_Carrara

3drendero said:

Thanks for the update Philemo.

Is a beta version planned?

Easier to setup some free shader packs in time for the full release...

Yes, Beta is planned this week for dielectric material (non reflective). I'm finishing testing and I need to start some kind of documentation. I found a bug today when using light domes If I don't found to much bugs, beta will be out tomorrow (Tuesday) or the day after for Windows 64 (OSX a few days afterwards).

Conductors (reflective) are planned for next week if everything get right.

chickenman

Philemo If you are Platinum club member the current monthly item is IRAY.

A lot of IRAY are based on the Metalic work flow from what I have seen.

https://www.daz3d.com/pergoda-venue

I will check tonight if there was a free shader pack that came out when they released IRAY.

magaremoto

philemo, this is where you should find iray shaders within D/S if I understand correctly your request

 

Philemo_Carrara

Thank you to you both. I'll have a look into that. If it's possible, I think an IRay shader importer would be a nice addon to this plugin. Anyway, I'm curious to compare rendering of the same material in IRay and in Carrara, in terms of results and render time.

chickenman

If you can map the IRAY to the Carrara shaders fields then LUXcore can use them as it can interprete the fields and convert to LUXCore materials.

Or if you can map to luxcore materials fileds that would work as well.

See luxcore thread https://www.daz3d.com/forums/discussion/50130/luxuscore-carrara/p1

 

Maybe Sheric Labs would point you to the direction he was going with LUXCore.

Alberto

Philemo said:

To do that, I have implemented the Disney Principle BSDR as a lighting model. I've choosen it because it (or a modified version of it) is widely implemented (Blender/cycle, Appleseed, Renderman and many other included countless game engines). So, it was just time Carrara got itsown version :-).

A needed one. It's wonderful, Philemo !

WendyLuvsCatz

iray uses the Nvidia MDL which has its own developers site and SDK, info etc which might be useful for integrating that

https://developer.nvidia.com/mdl-sdk

magaremoto

this should come in handy to better understand MDLs

http://www.mdlhandbook.com/

3drendero

Substance Player by allegorithmic is free and can export the needed maps (up to 4k). Some changes are possible in Player, maybe enough to create some freebie shader packs that are royalty free.

Comes with 8 materials to test and tweak...

EDIT

Found another freebie site with 88 PBR textures, ready to download from 2k to 8k and CC0 rights (Public Domain, free to use for anything).

http://www.cc0textures.com/home

Headwax

thanks Philemo

it's heart warming when geniuses (alt genii) like yourself are on the good side :)

 

Philemo_Carrara

Beta version is out here (Windows 64 only, sorry for Mac user, I'll try to provide an OSX version later this week).

You can find a basic documentation in this post

This is only the specular workflow. Metallic map are ignored for now. Next version will have it.