Cycling through color wheel

#1

I’m not seeing way to just cycle up or down through the color wheel.

For instance, if am at hue of 181, and want to cycle UP until I arrive at same hue I’m not seeing any way of entering hue value above 360, (541 in this example) or of defining a single full cycle.

Even when keyframing simple hue values, it seems to often want to cycle in the wrong direction and does absolutely absurd interpolations of S and V values even when no shift at all is called for.

Whle the color shader itself is animateable, I don’t see way of animating the hue specifically. I see mention in some threads of xpresso using rgb, and some other potential issues, but hoping I’m missing some relatively simple way of doing this… and especially hoping it’s doable via intuitive hue controls.

#2

All colours in c4d are stored as rgb. The shortest route from one colour to another is never to spin around the outside of the colour wheel, it is to take a straight line through the middle, thus picking up muddy and washed out colours. Your only option will be a filter shader and to then animate the hue value.

#3

I suspected something along those lines, though hadn’t heard of the filter shader. Looks like the kind of thing I should understand for other reasons too, so thanks for the heads up.

#4

There are a number of similar issues. Just spent the last couple hours chasing down issues where all I was doing was animating from one grayscale value to another, yet it kept drifting in and out of saturation values , flipping the hue to zero causing other issues, etc.

I understand the program doesn’t think in terms of hue or saturation, but what I’ve been dealing with today seems just plain unnecessary when other programs would have handled similar tasks intuitively and without issue.

Am I missing some bigger picture about how to address such issues? How do others deal with this?

#5

This might do what you want. Modulo means count up to and start over.

colorwheel.c4d (242.2 KB)

#6

Generally speaking I would make these sort of changes in post. So much quicker to slap an effect in Resolve, AE or Fusion using a matte. Of course, if the object in question is generating any GI or other bounce lighting then things become a bit trickier…