[Visualpython-users] how to rotate a frame inside a class?

[Stefan P. <ste...@ur...>]

When rotating a frame inside a class, it starts to move and rotates around 
some mysterious center.
I could not find out how to calculate origin for a propper offset. 

Please find attached my example. I would be glad for any hint. 

Thanks in advance, 

Mit freundlichen Grüßen / With kindest regards 

Stefan Paulick 


http://www.urbeli.com
mailto://ste...@ur...
/*----------------------*/ 

import time
import visual 

b = visual.box(height = .1)
c = visual.cylinder(pos=(2,2,2),axis=(2,0,0),radius=.1)
f = visual.frame()
d = visual.cylinder(frame=f,pos=(1,2,1),axis=(2,0,0),radius=.1)
e = visual.cylinder(pos=(0,0,0),axis=(2,0,0),radius=.1)
e.pos = (3,2,3) 

class cC():
   def __init__(self, pos=(0,0,0), axis=(2,0,0)):
       self.pos = visual.vector(pos)
       self.axis = visual.vector(axis)
       self.f = visual.frame()
       self.g = 
visual.cylinder(frame=f,pos=self.pos,axis=self.axis,radius=.1)
       self.g.pos = visual.vector(0,2,0)

   def wpos(self,local):
       x_axis = visual.norm(f.axis)
       z_axis = visual.norm(visual.cross(f.axis, f.up))
       y_axis = visual.norm(visual.cross(z_axis, x_axis))
       #return  x_axis,y_axis,z_axis
       return self.f.pos+local[0]*x_axis+local[1]*y_axis+local[2]*z_axis

u = cC() 

ax = 0
cnt = 0. 

while 1:
   print u.wpos((1,2,0))

   if ax == 0:
       c.rotate(angle=.15, axis=(0,1,0), origin=(3,2,2))
       f.rotate(angle=.15, axis=(0,1,0), origin=(2,2,1))
       e.rotate(angle=.15, axis=(0,1,0), origin=(4,2,3))
       u.f.rotate(angle=.15, axis=(0,1,0), origin=(1,2,0)) 

       c.color = (1,1,0)
   elif ax == 1:
       c.rotate(angle=.15, axis=(0,0,1), origin=(3,2,2))
       f.rotate(angle=.15, axis=(0,0,1), origin=(2,2,1))
       e.rotate(angle=.15, axis=(0,0,1), origin=(4,2,3))
       u.f.rotate(angle=.15, axis=(0,0,1), origin=(1,2,0))
       c.color = (1,0,0)
   elif ax == 2:
       c.rotate(angle=.15, axis=(1,0,0), origin=(3,2,2))
       f.rotate(angle=.15, axis=(1,0,0), origin=(2,2,1))
       e.rotate(angle=.15, axis=(1,0,0), origin=(4,2,3))
       u.f.rotate(angle=.15, axis=(1,0,0), origin=(1,2,0))
       c.color = (0,0,1) 

   cnt +=1
   ## print cnt,ax
   if cnt > 10:
       cnt = 0
       ax += 1
       if ax > 2:
           ax = 0
   time.sleep(.1)