all_int_lin_sur - Function

Calculates all intersect points between a surface and a line.


Description.

The function calculates all intersect points between a surface and a straight line. There are many options for the ordering of the intersect points.

Syntax

all_int_lin_sur(surface, p, v, order, start, nint, uv, xyz)

REF	surface;
VECTOR	p;
VECTOR	v:
INT	order;
VECTOR	start;
INT	nsol;
VECTOR	uv ( );
VECTOR	xyz ( );

Principal parameters

surface	- Identity of the surface
p	- Position
v	- Direction of the line (ray)
order	- Method for the ordering of intersect points (the solutions).
	Ordering is always with respect to the distance to the input R*3 point p    but solution points will be omitted for the different cases.    Eq. 1: All intersect points     Eq. 2: Only intersect points in the v (shooting) direction    Eq. 3: As 2 but only intersect points with surface normals that have the same direction as              the v vector (the shooting direction)    Eq. 4: As 2 but only intersect points with surface normals that are in the opposite              direction as the v vector (the shooting direction)    Eq. 5: As 3 but the number of solutions will be zero ( 0 ) if the first solution   point has a              surface normal that is in the opposite direction compared to vector v (the shooting              direction)    Eq. 6: As 3 but the number of solutions will be zero ( 0 ) if the first solution point has a              surface normal that is in the same direction as the vector v

nint	- Number of solution points

Optional parameters

start	- Start uv-value for faster numerical solution. vec(-1,-1,-1) = none = default
uv	- Array with output U,V solutions (intersect points)
xyz	- Array with output R*3 solutions (intersect points)

Example

VECTOR uv (10);

all_int_lin_sur(#5, vec(100,20,30), vec(1,0,0), 2, ,uv )

Calculates all intersect points between the line defined by point (100, 20, 30) and the vector ( 1, 0, 0)
and the surface #5. Output solution points in uv will only be the points in the shooting direction.