Color jitter - Random color

[Alexx31]

Vray needs a color randomization node as Arnold for example has!

[vlado]

You can add extra V-Ray attributes to a samplerInfo node; there is a random by node output that you can use to drive a ramp texture, for example.

Best regards,
Vlado

[Alexx31]

Thanks, I have found that yesterday, too. It is not the same and less handy.
- The results from using a ramp are of course good in the case, when you want to achieve very specific colors.
- But if you just want jittering only hue or only saturation or only gain, and tune it with a specific min/max, this is impossible with a ramp.
Just as an example: You either have a lot saturation or less saturation, but not both at the same time jittering, while you take all colors of the rainbow. The color space needs at least two parameters (U & V) to include all colors with all hue, all saturation, all values.
- And you have no Seed slider in vray: It means for each variation it again needs tuning and more nodes.
- Furthermore I was looking for a way to target each individual face instead of objects. Is there a way at the moment, without having to separate all objects?
- Another interesting feature would be to take a picture as sample space. This also needs U & V. If there is a way, too, let me know, thanks!

[AFGSC]

Any updates on this (3.6)?

[yolov]

For the moment, the options are to use the samplerInfo with the extra V-Ray outputs (and a ramp) or use the MultiSubTex. In both cases, you'll randomize between a predefined set of colors or textures and you'll need to specify them.
We have some plans for improvements in this area and we hope to get to this in the near future.

[Phantom-Studio]

You can achieve this with the Vlado's technique (sampler info + ramp), but instead of using the ramp for the color variation, use it as greyscale and output in a blend node (as mix value).Set the input 2 of the blend node with your base color. Connect the base color to a remap HSV, and this remap to the input one of the blend.

[Alexx31]

thanks to you!
I still think, that this requires a lot work in the node tree and would be really great to have it implemented just with one panel.

The sliders are intuitively and small and if you open such a scene file a after long time, you can immediately understand, what happened in the node tree.
It requires a lot abstraction to work with ramps, you have more potential error sources
and If you think of a scene with many objects, it gets really hard.
Maya is anyway hard enough

[dgruwier]

You can also just have the samplerinfo output drive the values in a colorCorrect node directly. Use a remapValue node in between to dial in the min/max.

Don't mean to try and shoot down the idea, just wanted to point out an even better way to do.

[BeneZ]

Wasn’t there with Vray 5 introduced something? Not sure, but remember to have seen a video...
Thanks for reply

[yolov]

I guess you may have seen the random hue/sat/gamma in MultiSubTex.
You can try just adding a MultiSubTex and you can add a single flat color (or texture) that can be randomized.

[woytha]

Just doing some trees and yep, quick randomization of hue (but also other stuff) would be handy. Something similar to hair shader.

[yolov]

You can use the MultiSubTex to randomize the hue/sat/gamma.
You can even pass a single color (or texture) value instead of a whole list of colors/textures and this will randomize the colors for every object that has this shader assigned.
If that's what you're after, you can give it a try with the MultiSubTex.