"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Kenneth" <kdw### [at] gmailcom> wrote:
>
> > Or perhaps I'm misunderstanding what the ShaderToy reference means, and why it
> > cautions against a 0.0 value in a color vector being multiplied.
>
> Yes, it is a bit hard, if not impossible to grasp the "why" without a greater
> overview of the context.
>

Ah yes, I see the reasoning now, particularly as concerns lighting and
radiosity: For example, a 0.0 in an object's color vector is like a 'black hole'
that absorbs any and all 'incoming' color for that color channel, no matter what
the incoming intensities are. Like a hypothetical 'super-black', which is
certainly not a realistic situation, and which was probably not intended anyway.

That's an interesting little problem that I had not considered before! I've
probably had a weirdly mistaken notion that a 'black object' in POV-ray like rgb
<0,0,0> would somehow show itself as 'dark gray' if a powerful-enough light was
shined on it, ha-- like a typical real-world black color. But I didn't think
through the details. :-<

Post a reply to this message