"Dave Blandston" <nomail@nomail> wrote:
> Hello,
>
> This is an old scene with some slight improvements. Getting the rainbow gradient
> right is tricky. Making a mathematically linear gradient doesn't seem to give
> visually linear results. The primary colors appear to dominate the secondary
> colors, causing uneven transitions. This scene uses a partial fix but it's still
> not perfect. I have seen what appear to be perfectly balanced rainbow gradients
> before - does anybody know the trick to getting it just right?

Somewhere (in the POV docs or elsewhere) you can find the relative intensities
for RGB values. I have no idea where to find that information anymore. I know
for a fact that green overpowers the other two.

Another thing you can try is to find an image of the gradient you want, and fill
up a color_map with the colors from it. You can use eval_pigment (slow), or you
can make a function from the image and test it directly. You might still have
gamma issues, but the result should be close to what you want.

~Sam

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