## rotation autour de l´axe des z

Like all linear transformations that command is in 2 modes:
direct and matrix.

## rotz obj

### rotz(an) obj(id) [poi(x,y)]

Rotates angle **an** around z axis with respect to the
point **(x,y)** (its center of gravity by default) the object
identifier **id**
### rotz(an) vertex(s) object(id)

Rotates the vertex **s** of the object **id** angle an around the z axis
with respect to its center of gravity.

**Note:**

object is **fog, light, traj, var, view, vol**.

**Examples:**

1) rotz(PI/2) poi(100,-20,50) vertex[1,5] vol(1,3): rotates around the z axis the vertices
(1,2,3,4,5) of the volumes 1 et 3 angle PI/2 with respect to point (100,-20,50).

2) rotz(PI/2) var("x"): rotates around the z axis the variable **x** angle PI/2
with respect to its center of gravity.

3) rotz(.1*PI) eye view(2): rotates angle .1*PI around the z axis the eye of the view 2.
### rotz(a1,a2)vol(a)rotz(b1,b2)vol(b)

Varies **rotz matrix vol(a)** in the interval **[a1,a2]** when
**rotz matrix vol(b)** varies in the interval **[b1,b2]**.

Can be used for attach the **rotz** variations
of volume **a** to those of its father **b**.

**Note:** **rotz(b1,b2)** may be any other transformation **transf(b1,b2)**.
## rotz image

### rotz(an)image(id)

Rotates image **id** angle **an** with around its center.

**Options:**

**col(r,v,b,t)**: complete with pixels color **(r, g, b, t)** (black and transparent by default).

**poi(x,y)**: normalized center of rotation (0.5, 0.5 default).

**rotz(an1,an2)**: vortex.
## rotz matrix

### rotz matrix vol(id)

Returns the z rotation angle of the volume **id** matrix.

**Options:**

**format(f)**: modulo **f**.
### rotz(an)matrix vol(id)

Rotates volume **id** angle **an** around the z axis by changing its matrix.

**Options:**

**ini**: from the basic transformation.
## roty view

### rotz(an)eye view(id)

Rotates angle **an** around the z axis the eye of the view **id**.
### rotz(an)aim view(id)

Rotates angle **an** around the z axis the aim point of the view **id**.

**Options:**

**validate(0)**: from the initial position.
## See also: