> I was in the book store tonight paging through Curtis Rhoades' (sp?) book
> on Computer Music and noticed a page with a picture of a surface being
> traced by an orbit.  I've had a small collection of complex 3D surfaces
of
> the form Z(x,y) which I wasn't sure how best to use to generate sounds. 
In
> the past I had just rastored through them snaking back and forth.  Using
> orbit opens up a large number of possibilities.  For example a circular
> orbit could trace along the surface and the Z(x(t), y(t)) is taken as the
> amplitude.  Modulations could be applied to the circle center point,
> circle->ellipse.  Instead of circular orbits chaotic oscillators could
> define the X, Y coordinates although these would not be tuned.
> 
> I think something like the following will work:
> 
> y=sin(t)
> x=cos(t)
> 
> Z(x, y)=sin^2*(sqrt(x^2+y^2))
> Z(x, y)=ln(x^2+y^2)
> Z(x, y)=x-1/12*x^3-1/4*y^2+1/2
> Z(x, y)=-5*x/(x^2+y^2+1)
> Z(x, y)=1/3*x^3-x*y^2
> etc...
> 
> These equations are from Clifford Pickover's "Computers and the
Imagination"
> Start oscil can be used to generate sine and cosine.  Then modulate by
> varying radius, center etc.  This opens up a large class of synthesis...


Can anyone please explain a little deeper how things like orbits and
circular path tracing can be used
with a Csound oscil ???

How do I let "move" the sound on a path  like one moves pixels in a
computer animation


David.