VRayColor - Fix please

[Morne]

Hi Guys

One of the previous iterations, worked great. As it stands now with Next (1.1), it's not great

Can we please get any of these:

1) Enable VRayColor to be displayd in viewport
2) Add another swatch, that shows the corrected colour (so we can pick it)
3) Bring back the previous functionality like it was in 3.6.04. Typically we would stick in a 2.2 gamma to adjust colors that was picked in PS. Then we would simply copy and paste the swatch to diffuse to get the correct display in viewport

[vlado]

Hm, interesting - I was under the impression that nobody used the gamma rollout. The parameters are still there and accessible from MaxScript, just the UI is hidden, will think about whether we should show it or do something else.

Best regards,
Vlado

[vlado]

Btw 3ds Max would automatically correct colors that you pick with the color picker. I usually use File > View image file... to open the image and pick the color from there.

Best regards,
Vlado

[kosso_olli]

You can actually pick any color on the screen with the color picker, even if its outside of Max. Great hidden feature!

[spyzor]

If you pick a color outside of Max you won't get the right color (as I remember). I always needed to import the image as a bitmap in 3ds max to pick it correctly.

[Morne]

Could you guys explain how to pick a colour outside max please, using max?
Typically we would be viewing either a website or a pdf. Saving that out to a jpg, then opening in max, sounds like lot of PT.
Typically we would screengrab what we need, then paste in PS and pick color in PS, then stick that into a VRayColor and adjust gamma.

[Vizioen]

Could you guys explain how to pick a colour outside max please, using max?
Typically we would be viewing either a website or a pdf. Saving that out to a jpg, then opening in max, sounds like lot of PT.
Typically we would screengrab what we need, then paste in PS and pick color in PS, then stick that into a VRayColor and adjust gamma.

When the colorpicker window appears, just click and hold on the color palette, then drag your mouse to the window where the image or whatever is you need to pick the color from. Works in a lot of applications like that.

[Morne]

When the colorpicker window appears, just click and hold on the color palette, then drag your mouse to the window where the image or whatever is you need to pick the color from. Works in a lot of applications like that.

That works, thanks

[marty030]

Hi,

I did not quite get if VrayColor is broken or if I could fix it by some .ini entry. Or is there a nightly fix?

It is safe to say where it worked before it does NOT after having upgraded to Update2. I wonder why...

As Autodesk is not capable of fixing this over a decade old issue by itself we need to rely on the VColor or ColorC. to circumvent Max´s gamma setting for colors.

Feel free to try it for yourself, in the image I lined up the examples. Basically the result you dial into Photshop should be visible in the MaterialEditor and Rendering.

[^Lele^]

It works perfectly fine with me: in the render below one lightMtl has the color, input as the RAL values in the color picker, and with gamma set to 2.2, while the other vrayLightMtl has the map you provided.
Try it with a more recent nightly, perhaps?


EDIT notice both the map and the vray color differ a bit when gammaed (i used a max bitmap in this case.), because the max bitmap loader uses the sRGB gamma curve (and can only use that.) while the vrayColor uses a pure 2.2 gamma curve.
When gamma is set to 1.0, the results match to the third decimal place (third image).
When using a vrayHDRI loader, and the gamma is set to a pure 2.2 curve in the color space dropdown (actually an inverse gamma of 0.4545), results again match to the last decimal place (minus the fact the bitmap has a Blue of 34, instead of 35. last image).

[marty030]

Installed Vray Update 2.1 with Max2020 and the issue still occurs. VRayColor does not work the way it did before Update2.

lele Feeding Bitmaps into the system is not the problem, but colors.

As Morne was pointing out and as you can see in the images setting up specific colors should result in a consistant way from ColorSlot-->ShaderBall-->Viewport-->Rendering.
The main problem is Max not working correctly with the colour input. Bitmaps were solved some time ago with the overhauled importer and gamma settings which are now hidden, as Vlado mentioned.
The solution (or workaround) to this so far was using VrayColor set to 2.2. in the slots related to color. (another was ColorCorrect or Max´ own ColorCorrection set to inverseGamma, both uncomfortable).

All we need is VRayColor to work as before. Please fix it.

[^Lele^]

Installed Vray Update 2.1 with Max2020 and the issue still occurs. VRayColor does not work the way it did before Update2.

lele Feeding Bitmaps into the system is not the problem, but colors.

As Morne was pointing out and as you can see in the images setting up specific colors should result in a consistant way from ColorSlot-->ShaderBall-->Viewport-->Rendering.
The main problem is Max not working correctly with the colour input. Bitmaps were solved some time ago with the overhauled importer and gamma settings which are now hidden, as Vlado mentioned.
The solution (or workaround) to this so far was using VrayColor set to 2.2. in the slots related to color. (another was ColorCorrect or Max´ own ColorCorrection set to inverseGamma, both uncomfortable).

All we need is VRayColor to work as before. Please fix it.

Can you show me how it used to work?

[marty030]

Sure, in the end it should like when using Max´ own ColorCorrection modifier:

[labulle]

We use VrayColor heavily and have huge issues with it in Vray Next.

I have finally managed to take a spreadsheet and attempted to see what's going on.

We have two ways we could input a color into VrayColor : float values and color swatch.
Each input updates the other.
In the end, we want to input gamma 2.2 corrected RGB values (from let's say Photoshop) and let Vray translate them to its linear space (please correct me if my understanding is wrong).

There comes the interesting part. When I input a float value of 0.5 in a channel, in linear space it equals to 128 but in RGB corrected space it should output ((128/255)^(1/2.2))*255 = 186. So when I do that and check the color swatch (defaults values and fresh install of vray and 3ds max), my output is 186 and everything's fine.

However, if I move the value in the color picker, my float value updates to 0.866 for the same RGB value of 186 !
And the weird thing is that's exactly what should happen if VrayColor applied the SAME gamma correction also in that way, and that should obviously not happen . So let's check it out : (186/255)^(1/2.2) = 0.866

If I understand it correctly, it's a bug, as VrayColor should take the gamma corrected swatch value and UNcorrect it, not apply a new gamma correction on top of the first one !
If so, could it be quickly fixed please ?

Thanks !

EDIT : maybe should I post it in the Issues forum ?

[vlado]

You could set the "color gamma" of the VRayColor parameter to 2.2 and you will get the results that you want, but in general it looks like you are looking for a color picker that allows you to enter sRGB-corrected colors and will uncorrect them automatically. The 3ds Max color picker doesn't have this option; the Corona one does and we've been thinking about including it with V-Ray as well. That advanced color picker has a "sRGB" checkbox that allows you to do exactly what you want.

Best regards,
Vlado