Color variation map for instances

[trick]

I don't know if this has been asked before, but I would like to see a color variation map (that can variate HSV values and possibly use colors from a preset gradient) for random coloring materials on instances/proxies!!!

[vlado]

It is not really that difficult to write one... I can try to think of something.

Best regards,
Vlado

[cecofuli]

Hi,

yes, this is a great addon for proxy obj

[RErender]

It would be nice to have an easy way to vary a lot of proxies, especially when used for trees and plants.

I worked out a method where an objects vertex colors were wired to it's position, then a vertex color map could be used to vary the material. Maybe a map that varies it's grayscale output depending on a proxies position would do the trick.

[trick]

It is not really that difficult to write one... I can try to think of something...

If it is not that difficult please do ! I use HDInstance (a volumetric instancing pluging) for Lightwave that uses random coloring by using a custom gradient and also Thinking Particles has a Variation Map (which will soon be integrated in FinalRender), which all make for more realistic images, especially when huge numbers of instances are required.

[vlado]

What do you think should be the controls for this map? I was thinking that it should have at least a base color and H/S/V variation amounts. Can you think of anything else?

Best regards,
Vlado

[Lehm_2001]

This is a great idea. Any chance of implementing this also as a material slot in the VrayProxy max object? Just in case you don't want to mess with the original material for whatever reason.

[vlado]

It is not impossible, but I can do it reliably only for V-Ray compatible materials.

Best regards,
Vlado

[cecofuli]

Hi Vlado,

i don't know if this can help you, but sometimes i use this script:

HSV Color Randomizer

It's very handy.

And, if you add some Map control (procedural or BMP),
this is better better... In this mode, i can select exactly the area that i want to change the color.

bye

cecofuli

[RErender]

What do you think should be the controls for this map? I was thinking that it should have at least a base color and H/S/V variation amounts. Can you think of anything else?

Best regards,
Vlado

Maybe some different "seeds" like world xy , elevation, scale, bitmap?

Camera z to reduce displacement etc. over distance

[vlado]

I was thinking to use the node render id's as random seeds; you can use procedural maps for all the other stuff.

Best regards,
Vlado

[trick]

What do you think should be the controls for this map? ...

Basically each instance should get its own color. Mostly proxies have MultiSubobject materials, but with trees you mostly want to only change the color of the leaves. So the coloring should happen at material level. Next to that it would be better if a map could recognice subobject elements and randomize colors there too, but independant from the coloring per instance. So for trees you would need a base color (say yellow) and percentages for randomizing the HSV values and you would get trees with colors in the orange-yellow-green range, some darker/lighter, some more/less saturated. If you wanted the leaves within one proxy/tree have different color values (darker-light, more-less sat), you would need element recognition.

With lots of cars there comes another problem. If you wanted the broadest color range you would probably set colors for the whole spectrum, but then you would also get pink, yellow, and lots of other colors you would not want. So you should be able to set your own colors or color ranges. Either by loading a selfmade image map where colors are chosen from or making a custom gradient system in which you can specify colors/ranges. Another thing that could help would be a mapped image (either by UV, front- or whatever mapping) that defines the tinting by local (to the instance) or world location (which could require you to pick another object). This way you could only have a parking lot for green, red and blue cars and their darker/lighter, more/less saturated variants.

Suppose you have lots of cars and in your image there is an ugly red car in the foreground. By setting some random value you can redistribute the colors for all the cars until you see what you like.

In a perfect world proxies should be randomly animateable by loading their transform from a saved point cache map, this transform could be tied to the distance travelled along a path (place on path defines place in point cache map), and each would would have their own color value. With a particle system and a looping walking man (in place), you could generate a complete crowd based on proxies, where each has its own color and marches at its own speed !!

[muzzy]

Final render has a variation tex map on this video, same thing what we are taking about just HSV variation with bitmap support

http://cebasusa.com/m_o_v_e_e/Trees/trees.html

[trick]

Final render has a variation tex map...

This is a basic shader that comes with Thinking Particles, but will be integrated in the next release of fR or fShaders...

[trixian]

How about random UV offsets and rotations for bitmaps?
(For objects that aren't necessarily trees).