# eval3dp

compute facets of a 3D parametric surface

## Calling Sequence

    [Xf,Yf,Zf]=eval3dp(fun,p1,p2)

## Arguments

Xf,Yf,Zf

  matrices of size (4,n-1*m-1). `Xf(:,i)` ,`Yf(:,i)` and `Zf(:,i)` are respectively the x-axis, y-axis and z-axis coordinates of the 4 points of the ith four sided facet.

fun

  a Scilab function.

p1

  a vector of size `n`.

p2

  a vector of size `m`.

## Description

`eval3dp` computes a four sided facets representation of a 3D parametric surface defined by the function `fun`. `fun(p1,p2)` computes the x-axis ,y-axis and z-axis coordinates of the corresponding points on the surface, as [x(i),y(i),z(i)]=fun(p1(i),p2(i)). This is used for efficiency.

## Examples

    p1=linspace(0,2*%pi,10);
    p2=linspace(0,2*%pi,10);
    deff("[x,y,z]=scp(p1,p2)",["x=p1.*sin(p1).*cos(p2)";..
                               "y=p1.*cos(p1).*cos(p2)";..
                               "z=p1.*sin(p2)"])
    [Xf,Yf,Zf]=eval3dp(scp,p1,p2);
    plot3d(Xf,Yf,Zf)

p1=linspace(0,2*%pi,10); p2=linspace(0,2*%pi,10); deff("[x,y,z]=scp(p1,p2)",["x=p1.*sin(p1).*cos(p2)";.. "y=p1.*cos(p1).*cos(p2)";.. "z=p1.*sin(p2)"]) [Xf,Yf,Zf]=eval3dp(scp,p1,p2); plot3d(Xf,Yf,Zf)

## See Also

- genfac3d
- plot3d