rotate with vex around axis next to the object

[jon3de]

hi,

I know how to do some basic rotations with vex although the objects is always rotation around itself. Is it possible to do the same thing but use an external rotation point e.g. one of the corners of the box ?

 

[dchow1992]

offset position, rotate, subtract offset

[fsimerey]

And you can do more. Rotate along the vector defined by 2 specific points in full 3d:

// Points to define vector axis and center
vector P0 = point(0, "P", chi("p0_axis"));
vector P1 = point(0, "P", chi("p1_axis"));
vector axis = normalize(P1 - P0);
vector center = P1 - (P1 - P0) / 2;

// offset to center
vector _P = @P - center;
float ang = chf('angle');
vector4 q = quaternion(radians(ang), axis);

// rotate P and N
@P = qrotate(q, _P);
@N = normalize(qrotate(q, @N));

// replace to origin
@P += center;

 

Edited January 30, 2017 by fsimerey
Correction for center