Color value in node materials

[Makushimu]

I noticed that the copied color values from the standard material to the nodal material are not pasting correctly.
Additionally, standard and nodal materials are displayed differently in the viewport, disregarding the same color values. But that's less of a problem.
If I set the same color for the layer for the object, the color is displayed correctly in the viewport.

https://streamable.com/vmyvpp

[shaio]

Hey Makushimu

Thank you for the feedback.
Unfortunately the same issue exist if you copy a color from the Cinema 4D Standard Material to their Node Material as well, meaning taht the difference comes somewhere from Cinema 4D not V-Ray in general. We will of course look in to it and see if we can do something but still keep in mind that this isn't V-Ray related.

[shaio]

I've investigated this a bit more and even with the fact that the Cinema 4D Standard and Node materials do have different color values in the editor their final result with the Standard Renderer is the same where with V-Ray it isn't. The Node Editor materials always display and render the color values in the Linear Color Space where in the Classic Materials this isn't the case.
We will look in to this and fix it with priority.

[Makushimu]

I've investigated this a bit more and even with the fact that the Cinema 4D Standard and Node materials do have different color values in the editor their final result with the Standard Renderer is the same where with V-Ray it isn't. We will look in to this and fix it with priority.

Yes, later on I noticed that the wrong copying of values is also in the c4d native materials.
Besides, if you could fix it so that the display was the same, it would be great.
Thank you.

[shaio]

Hey Makushimu ,
we've fixed the issue and this fix is available in the latest stable builds. You can download it from here: Nightlies (chaosgroup.com)

[Makushimu]

Hey Makushimu ,
we've fixed the issue and this fix is available in the latest stable builds. You can download it from here: Nightlies (chaosgroup.com)

Thanks.

I just downloaded the July 20 version from your link, although it appears as the 19 version in c4d and I'm testing it.
However, it still seems to me not to be fixed fully.
Coping value is fixed indeed, but there are still differences in the viewport, material preview and the renderer when the value is the same in both types of material. I am attaching a screenshot.

[deyan.hadzhiev]

Hi Makushimu, the difference you are observing is caused by the new option in the color input fields for the node materials. There is a toggle for showing either the linear values or the color corrected values. In your example the toggle is its default state, which uses the linear values. This differs from the values in the classic materials, which are shown in the document input color space, which by default is sRGB. You can see the difference in the screenshot I'm attaching, with the toggle using color corrected values.


You can see in the second image, that when the Input Color Profile of the document is changed to linear, setting the same values of the color in the node color input (while the value display toggle is set to linear values), the result is again the same.



The important thing to remember is this - the global document setting for Input Color Profile affects all color inputs of Classic materials, while the color values in nodes are always stored in linear color space and the toggle only changes the displayed values in the user interface.

I hope this clarifies your observations.

[Makushimu]

Deyan.hadzhiev thank you for your comprehensive answer. This solves the topic for me.

[index]

can't delete the post... still need to evaluate

[index]

Ok, i did quite some tests on this the last two days but i keep this as short as possible now...
it was originally posted in this thread but i post here now, because this thread was mentioned as answer.

Again, if you create two default Vray-5 Materials (not Node Materials)
Material A diffuse add a Color Shader with RGB 0.5, 0.5, 0.5, Brightness 1.0
Material B diffuse add a Color Shader with RGB 1.0, 1.0, 1.0, Brightness 0.5
--> they should look the same, but do not in Vray 5 !
--> the brightness of 0.5 must get converted to Linear which is 0.214, then A+B look the same

As said by Support this resolves when switching to Color Space Linear,
but it should maybe considered that ...

- most people probably work in sRGB, so they are getting unexpected results
- this does not happen with Cinema4D Materials in sRGB space !

Also, there is a second issue with brightness, probably not related to sRGB.
So both in sRGB and Linear it is not reliable to use the brightness slider atm.
(to be confirmed)

( Btw, is there any Info on how to work in Linear Color Space?
bc if you enter an RGB value in this mode, you don't get the expected color. )


Vray 5.20.05 / Update 2.5

[index]

After additional input value tests regarding
the Layer / Layered Shader blend / opacity value and the Multiplier / Mix Strength values,
I was surprised that also in C4D you need do use Linear values in these places !

Here my results about the expected input value modes (in Color Space sRGB)

	C4D	Vray3	Vray5
Color Brightness	sRGB	sRGB	Linear !!
Multiplier / Mixmode	Linear	sRGB !!	Linear
Layer Blend / Opacity	Linear	Linear	Linear

Is this different handling of the Brighness really intended?

[aleksandar.kasabov]

Hello index,

The reason for the differences in the colors when the input color is set to sRGB is because the color transformation is applied before the brightness value. For the node materials, Maxon have added a setting in the color picker to show linear values. I hope this is of help.

[index]

hi, aleksandar... i understand whats happening.
i just find it odd that a low-level thing like the brightness doesn't match the native Cinema 4D material workflow.
but i got it, case closed.

[aleksandar.kasabov]

Hello index,

We don't have brightness as a parameter in V-Ray and therefore it cannot be compared with the brightness in the C4D materials. The reason why C4D has the same results is that the brightness is applied before the color transformation. I hope this makes sense.