|
![](/i/fill.gif) |
I've been trying to generate a new kind of pattern by use of macros and am
unable to use the individual coordinates of the point being evaluated for
the pattern.
This works:
#macro crn()
(x - int(x))
#end
This does not:
#macro crn()
#declare a = int(x);
(x - a)
#end
Why?
What I want to do is get the x, y, and z values of the point being evaluated
by pigment{function{crn()} and use them as they were floats, not vectors.
I need them for array indices as my noise resembles Perlin in its
calculation, but uses a catmull-rom spline (smoother noise, more control
points) instead of cubic.
Some years ago I modified Povray source, swapping the internal noise
function for the catmull-rom version, but I could only compile in DOS. I
tried to get it into MegaPov but the development of Povray 3.5 prevented
it.
Post a reply to this message
|
![](/i/fill.gif) |
|
![](/i/fill.gif) |
"Serious Putty" <nomail@nomail> wrote in
news:web.3f08e54f2a66c56848cb617a0@news.povray.org:
> I've been trying to generate a new kind of pattern by use of macros
> and am unable to use the individual coordinates of the point being
> evaluated for the pattern.
>
> This works:
>
> #macro crn()
> (x - int(x))
> #end
>
> This does not:
> #macro crn()
> #declare a = int(x);
> (x - a)
> #end
>
> Why?
>
> What I want to do is get the x, y, and z values of the point being
> evaluated by pigment{function{crn()} ...
Because macros are only executed at parse-time.
It also seems like you are trying to make some kind of local
variable for your function with the #declare a = int(x) statement.
But functions cannot have local variables.
Tor Olav
Post a reply to this message
|
![](/i/fill.gif) |