# axis

## axis

### axis(x1,y1,z1,...,x5,y5,z5)

Returns:
The three unit vectors (tangent, normal and binormal) the Frenet frame of the curve M1M2M3M4M5 in M3.
The center of curvatureand the radius of curvature.
axis(x1,y1,z1,...,x5,y5,z5) ext(e,c,f)
Allows control coefficients (e, c, f) the extension curve used (e = 3, c = 1, f = 0 by default).
Exemple: axis(x1,y1,z1,...,x5,y5,z5) ext(7,1,0) gives better results.

## axis fog

### axis fog(id)

Returns the axis of the fog id.

### axis fog(id)=x1,y1,z1,x2,y2,z2

Defines P1(x1,y1,z1)P2(x2,y2,z2) as fog id axis.

## axis light

### axis light(id)

Returns the direction of the spot light id.

### axis light(id)=x,y,z

changes this direction.

## axis matrix

### axis matrix vol(id)

Returns the axis of the matrix of volume id.

### axis(x,y,z)matrix vol(id)

Change this axis.

## axis vertex

### axis vertex(s)vol(id)

Returns the axis (dx,dy,dz) associated with the vertex num of volume id.

### axis vertex(s)vol(id)=dx,dy,dz

Change this axis.
Note: If the volume id is a particle system, and if a volume v is associated with the vertex s the axis of this volume will be (dx, dy, dz).
An application example is given in the demo demo1_particle.func.

## axis view

### axis view(id)

Returns the direction of the view id.

### axis view(id)=x,y,z

changes this direction.

## axis vol

### axis vol(id)

Returns three unit vectors defining landmark volume id.
By default: (1,0,0, 0,1,0, 0,0,1). axis vol(id)=x1,y1,z1,x2,y2,z2,x3,y3,z3
Redifines these 3 vecteurs.

### axis vol(id1)axis vol(id2)

does: axis matrix vol(id1) = axis matrix vol(id2).
Note: does automatically this feature by:
attach(0)axis vol(id1)axis vol(id2)

### axis vol(id)poi(x,y,z)

Tends to move the volume id axis through the point (x, y, z).
Options:
axis(ax,ay,az): the axis of the volume is replaced by (ax, ay, az) (0, -1,0 default).
force(f,v): the operation is performed dynamically via a force rota f viscosity v. It is necessary that the volume id is equipped with a mass and yes dynamic is active.

### axis vol(id1)vol(id2)

Tends to move the axis of id1 volume through the center of gravity of id2 volume.

### axis vol(id1)vertex(s)vol(id2)

Tends to move the axis of id1 volume through the s vertex of id2 volume.

### axis vol(id)mouse

Tends to move the axis of id1 volume through the mouse position.
Options:
force(f): by a force rota amplitude proportional to f (default 1.0). Should theid volume is a dynamic mass and yes dynamic is active.
vertex(s): tends to move the axis joining the center of gravity of id volume and the s vertex so it throughs this positiuon.