Quaternion rotation

[Tudor]

Hello friends,
I'm trying to work with the Quaternion-Object.
My cam-Object should align to the direction vector and pointed in this case in X-Direction.
But if print the q.v value I get a zero vector and the rotation is not applied
Does I misunderstood the Quaternion-Syntax? I can't find nothing about that.
–
Thanks

import c4d

cam = op.GetObject()

def main():
    direction = c4d.Vector(10,0,0).GetNormalized()
    angle = 0

    q = c4d.Quaternion()
    q.SetAxis(direction, angle)
    b = q.GetMatrix()
    b.off = cam.GetAbsPos()
    cam.SetMg(b)

    print q.v

[r_gigante]

Hi Tudor,

actually your code is properly behaving, since the angle is set to 0. If, by chance, you set it to PI/2 you will immediately see that the camera promptly rotates and point up to the sky.

Hope the screenshot clarifies the situation

Best, Riccardo

[Tudor]

I thought I can use this direction vector as Quaternion-Axis. The cam should point than to the target.
But but it seems i need a different approach.

import c4d, math

cam = op.GetObject()
target = op[c4d.ID_USERDATA,1]

def main():
   tarPos = target.GetAbsPos()
   camPos = cam.GetAbsPos()


   direction = (tarPos - camPos).GetNormalized()
   angle = math.pi/2  #?

   q = c4d.Quaternion()
   q.SetAxis(direction, angle)
   b = q.GetMatrix()
   b.off = cam.GetAbsPos()
   cam.SetMg(b)

[r_gigante]

Hi Tudor, that's indeed not the way to proceed.

Quaternion is just a tool to conveniently represent a rotation in the space. That said the approach you need to follow is just to rotate the camera until it points where your target is.

Cheers, Riccardo

[a_block]

Hi,

please, do not delete discussions threads. The contained information might be valuable for future readers.

Cheers,
Andreas