Basic PBR Shader Set-up

frank beckmann

frank beckmann

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Basic PBR Shader Set-up

Here´s just a quick hint on setting up a basic image based PBR-shader:
Cheetah3d v7 PBR Set-up.jpeg

Cheers
Frank
 
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I loose my preview with this setup.
It turns into a black blob, but it renders good.

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Mmh - as you can see in my screenshot all looks fine&dandy so far. Sometimes the material preview needs a little nudge to update - like turning intensity up+down e.g.
Or if you´re talking about the 3d-view? If you want to see at least the base image texture you have to bypass every node between it and and the PBR-node - unfortunately. But for a material preview in 3d-view we/Martin need/s another OpenGL version I think.

Cheers
Frank
 
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Here's my setup, default settings on the mix node.

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  • Bad Preview Setup.jpg
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Ok I got you, I was getting the preview because I was running the base color
directly into the diffuse channel, no problem to switch when needed.

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I believe the height image is meant for the "displacement-modifier" and any manually set value will be overwritten by the connected image node though.
The bluish/violet image (normal map) should work as a bump map set to "normal/OpenGL".
Fun t mix up with the images - interesting results:
MixedImageMaps.jpeg

Cheers
Frank
 
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Thanks Frank for the trick with the displacement modifier - I would have missed that possibility.

When there is no no distinct metallic map (most of the free materials have an all black image there) then switching to the old material node output shows not much difference in the render.
 
I REALLY have to get my head into the node material system. I've never used anything like it, so never quite sure where to start.

This is very interesting, though! Thanks!

Bob
 
I may very well be wrong, but I'm curious if it would be more appropriate for an AO map to be 'multiplied' with the Colour map for the Base Colour input rather than 'mixed'?

Also just an observation - it seems like including the AO map sometimes makes the material render a little too dark.

--shift studio.
 
But you can have a certain amount of AO by adjusting the "Mix:"-value - which I find pretty convenient.
AO amount.gif

Cheers
Frank
 
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frank beckmann said:
But you can have a certain amount of AO by adjusting the "Mix:"-value - which I find pretty convenient.

Cheers
Frank
Click to expand...

I was playing with that too. Just change the brightness value of Colour 0. Is that what you mean? You would need to be aware of giving colour 0 a brightness that is brighter than corresponding pixels on the Colour map - right?
If you used multiply and maybe a gradient filter for adjustment first, you could fine tune without worrying about that. Agree? I guess this would only be important if your base colour is quite dark...
Anyway, I'm okay, but no expert with the node system - I fumble around a lot - so I may be off base here.

--shift studio.
edit: added a screen grab, and pointed out where you can tweak.
 

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As you see in the GIF the white tones of the AO texture are skipped:

Cheers
Frank
 

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  • MixColor.png
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yes you're right, adjusting in image mode is easier than adjusting a gradient then multiply.

Now, isn't 'multiply' a theoretically better way to blend the maps than 'mix'?
 
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I've added a "Ambient occlusion" channel to the PBR shader to simplify the usage of ambient occlusion textures. It will be available in v7.3b2.

I would have needed that AO channel anyways for the full glTF material support.

AO textures are only needed when you work with bump/normal mapping. When you work with real displacement mapping the self shadowing of the mesh is a simple side effect of the displaced surface.

Bye
Martin
 

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Martin said:
I've added a "Ambient occlusion" channel to the PBR shader to simplify the usage of ambient occlusion textures. It will be available in v7.3b2.

I would have needed that AO channel anyways for the full glTF material support.

AO textures are only needed when you work with bump/normal mapping. When you work with real displacement mapping the self shadowing of the mesh is a simple side effect of the displaced surface.

Bye
Martin
Click to expand...

Excellent - thank you!
I was thinking the same when using displacement mapping (that AO is taken care of by geometry)

Now we just need displacement mapping as a channel too (to be implemented at render time?) - so that we don't need such dense meshes to use with the displacement modifier - I'm guessing thats more complicated than I make it sound - haha!

--shift studio.
 
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