Is there anything similar to the validation filter in subtance designer/painter in Vray?

[DanSHP]

Oh boy, I guess I will regret this but I just can't resist:
https://forums.chaosgroup.com/forum/...scans-material
May gods of sampling have mercy upon my soul

To save myself let me say: I know that is probably the exception rather than the rule.


DanSHP
You measure the rgb output in that dome light/sphere setup. No need for the rawDiffuseFilter element to get the correct albedo. It includes everything: layered shades, sss, reflection. That's the beauty about that method.
I'm thinking they most likely measure those values at an angle of approx 0. So the middle of the sphere would be the spot you'd want to keep around what ever albedo you found on the internet. The grazing angles will be brighter because of fresnel.

Cheers!

but also, in Environment -> Exposure Control -> <no exposure control>? Right?

[Ihno]

Cheers!

but also, in Environment -> Exposure Control -> <no exposure control>? Right?

Jup, nothing!
I use the standard camera in orthographic mode. But max physical camera without exposure would also do I think.
Be careful if you move to next, the vrayPhysicalCamera doesn't need the exposure to be set in the environment window. There is a checkbox in the camera settings.

[DanSHP]

Jup, nothing!
I use the standard camera in orthographic mode. But max physical camera without exposure would also do I think.
Be careful if you move to next, the vrayPhysicalCamera doesn't need the exposure to be set in the environment window. There is a checkbox in the camera settings.

Many thanks!

So to recap.

Camera.
Sphere.
Domelight at 1.
Turn off camera exposure in environment tab.
Texture in material diffuse (any need for maps in refl/glos/bump?)
Apply material to sphere.
Colour mapping? On none?
Render.
Pixel sample center of sphere.
Change RGB output of texture to reach desired colour float value.

[Ihno]

Camera. "not necessary"
Sphere. "give it many segments"
Domelight at 1. "Jup"
Turn off camera exposure in environment tab. "Jup"
Colour mapping? On none? "vray default setting exapt timelimit"

The rest depends on the data you have and the type of material you want to create.
Note that this is a setup to check the albedo (as been said Diffuse+reflection+sss).
You'll need to put the materal in different situations (like the good old shaderball scenes) in order to judge the glossiness for example.

[DanSHP]

Camera. "not sesessary"
Sphere. "give it many segments"
Domelight at 1. "Jup"
Turn off camera exposure in environment tab. "Jup"
Colour mapping? On none? "vray default setting exapt timelimit"

The rest depends on the data you have and the type of material you want to create.
Note that this is a setup to check the albedo (as been said Diffuse+reflection+sss).
You'll need to put the materal in different siturations (like the good old shaderball scenes) in order to judge the glossiness for example.

thank you very much!

[^Lele^]

Oh boy, I guess I will regret this but I just can't resist:
https://forums.chaosgroup.com/forum/...scans-material
May gods of sampling have mercy upon my soul

To save myself let me say: I know that is probably the exception rather than the rule.

Ahaha, yeah, you bumped into one *very* old sample, lol!
When i measured the vrscans, a few which had coating (procedural, plussed on top, and were of the very very early batches) exceeded 1.0f
The issue was well fixed, but those scans were never removed from the library.
Will make a note and see if we can get rid of them, or replace them with analogous ones.

[^Lele^]

Anyway, my point was just it might make sense to compromise and just treat this as a feature request for an albedo render element.

It's my conviction it'd hamper more than aid, and confuse more than clear up, that's all.
There are better ways, just not ready yet.

[^Lele^]

Yes, you are right, but they are sometimes referred to one another in the same fashion. Right? Another layer of confusion :P

Eheh, it's called "diffuse reflection" as nature doesn't really differentiate, and the term is taken from physics (cfr here): "[...] the measure of the diffuse reflection of solar radiation out of the total solar radiation received by an astronomical body (e.g. a planet like Earth)."

Can I actually measure an albedo texture for albedo if there is some form of reflection property included within it? For example an asphalt texture from textures.com (See attached.) I can't just throw this into the diffuse slot in Max as it is? I've always been under the impression, that all lighting and reflection properties should be removed from an image placed in the diffuse slot. So I'm a little confused.

The texture will have the whole natural reaction to light unless it was specially processed (f.e. with polarisers to cut of specular reflection), and then it'd have the companion texture which contained what was extracted to be put in the reflection slot.
Meaning the best one can do with just a standard texture is, indeed, to slap it into the diffuse component, and let it be it: any added reflectivity will be on top of the one existing in the original material from which the texture was created.
Of course, one can well eyeball the two components, slap the texture in the diffuse, darken it a bit, and finally add the reflectivity, so to go back to roughly the same original albedo of the texture.
Hardly ideal, but proven to work visually fine for simple enough shaders (often helped by bump).

Also when you say the "sum of my components need to hit that 0.04", what exactly do you mean by this? If I take my texture that has been measured to approx 0.04, I then just place this in the reflect slot and half it? So, in order to get my asphalt texture to 0.04 on average in the albedo test scene, I have to lower the RGB output value to something like 0.79. I just halve this number? so 0.395?

yeah, that's about right.
Of course, no one really knows the exact distribution between the two, so it's more eyeballing.

Thanks for your help regarding this, I apolgise if what I am asking is rudimentary stuff.

It's anything but rudimentary stuff!
Consider only us and xRite (Pantone, ya know?) have a real-life material scanning technology (Of the BTF type. others simplify a bit.), and that both of are very much at the bleeding edge of what is physically possible.
Results vary quite a bit between camps, as do the machinery and techniques.
I'd say us artists are well excused any and all the doubts we may have.

[dgruwier]

What are the better ways?

[^Lele^]

What are the better ways?

Once we'll settle on the approach, you'll know.

edit: but you could do worse than taking a look here