Every point in space can be thought of as either a point or a vector
between the origin and that point. The function probably is doing the
latter.
Euclidian space always has this dual-interpretation, but my
understanding is that Affine spaces do not.
-JK
On Apr 4, 1:46=A0pm, Jason <jdouce...@[EMAIL PROTECTED]
> wrote:
> I am reading a computer graphics book which contains information
> admittedly written originally as a technical paper, and uses RenderMan
> code to explain an algorithm, without explaining what the code does or
> what the variables mean. I don't know RenderMan code, but with a bit
> of research, I've figured out what most of the code does...
>
> I am lost in the length() function, though. =A0The RenderMan spec says
> it returns the length of a vector, but the code p***** it a point. =A0I
> assume it converts the point into a vector, but what is this other
> point?
>
> Is it the origin (0,0,0)?
> Is it a global variable? =A0(The length() function is called from within
> a 'volume' function, in case this matters.)
>
> Any help is appreciated!
> Thanks,
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