Thread: [Visualpython-users] issues with rotations

I wrote a little program to get an understanding of the rotation of objects
and have not been able to get things to work as I would like. I cannot get
objects rotate about their centers. Believe is some code where I am trying
to get a sphere to rotate about the x-axis while maintaining a 2 unit
distance from the yz-plane.


Any assistance would be greatly appreciated.

from visual import *
from time import sleep

#create a set of axes for a visual reference when rotating
xaxis=cylinder(pos=(0,0,0), axis=(5,0,0), color=(1,0,0), radius=0.2)
yaxis=cylinder(pos=(0,0,0), axis=(0,5,0), color=(0,1,0), radius=0.2)
zaxis=cylinder(pos=(0,0,0), axis=(0,0,5), color=(0,0,1), radius=0.2)

#create the ball to be rotated
ball = sphere(pos=(2,2,0), radius = 0.5)

#set rotation angle for 1/20 of a rotation
rotationAngle = 6.28/20.0

#have the ball rotate about the x-axis while
#maintaining 2 units from the xy-plane

for i in range(20):
    ball.rotate(angle=rotationAngle, pos=(2,0,0), axis=(1,0,0))
    sleep(0.2)

thanks again,

Mike

-- 
Michael Zittlow
Mathematics Department Chairperson
Southern Door High School
Brussels, WI 54204

Your ball is rotating about the default origin, which is the ball's pos.
Change your rotate statement to say origin=(2,0,0) instead of pos=(2,0,0).

It's better form to say rate(5) rather than sleep, for subtle reasons.

Bruce Sherwood


On Fri, Dec 28, 2012 at 6:55 AM, Zittlow, Mike <
mzi...@so...> wrote:

> I wrote a little program to get an understanding of the rotation of
> objects and have not been able to get things to work as I would like. I
> cannot get objects rotate about their centers. Believe is some code where I
> am trying to get a sphere to rotate about the x-axis while maintaining a 2
> unit distance from the yz-plane.
>
>
> Any assistance would be greatly appreciated.
>
> from visual import *
> from time import sleep
>
> #create a set of axes for a visual reference when rotating
> xaxis=cylinder(pos=(0,0,0), axis=(5,0,0), color=(1,0,0), radius=0.2)
> yaxis=cylinder(pos=(0,0,0), axis=(0,5,0), color=(0,1,0), radius=0.2)
> zaxis=cylinder(pos=(0,0,0), axis=(0,0,5), color=(0,0,1), radius=0.2)
>
> #create the ball to be rotated
> ball = sphere(pos=(2,2,0), radius = 0.5)
>
> #set rotation angle for 1/20 of a rotation
> rotationAngle = 6.28/20.0
>
> #have the ball rotate about the x-axis while
> #maintaining 2 units from the xy-plane
>
> for i in range(20):
>     ball.rotate(angle=rotationAngle, pos=(2,0,0), axis=(1,0,0))
>     sleep(0.2)
>
> thanks again,
>
> Mike
>
> --
> Michael Zittlow
> Mathematics Department Chairperson
> Southern Door High School
> Brussels, WI 54204
>
>
> ------------------------------------------------------------------------------
> Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and
> much more. Get web development skills now with LearnDevNow -
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>
>

Hi,

use origin instead of pos!
Hans

from visual import *
from time import sleep

#create a set of axes for a visual reference when rotating
xaxis=cylinder(pos=(0,0,0), axis=(5,0,0), color=(1,0,0), radius=0.2)
yaxis=cylinder(pos=(0,0,0), axis=(0,5,0), color=(0,1,0), radius=0.2)
zaxis=cylinder(pos=(0,0,0), axis=(0,0,5), color=(0,0,1), radius=0.2)

#create the ball to be rotated
ball = sphere(pos=(2,2,0), radius = 0.5)

#set rotation angle for 1/20 of a rotation
rotationAngle = 6.28/20.0

#have the ball rotate about the x-axis while
#maintaining 2 units from the xy-plane

#allows viewing and zooming before the start of the loop
s = input("type number to start:")

for i in range(20):
     ball.rotate(angle=rotationAngle, origin=(2,0,0), axis=(1,0,0))
     sleep(0.2)







Am 28.12.2012 14:55, schrieb Zittlow, Mike:
> I wrote a little program to get an understanding of the rotation of 
> objects and have not been able to get things to work as I would like. 
> I cannot get objects rotate about their centers. Believe is some code 
> where I am trying to get a sphere to rotate about the x-axis while 
> maintaining a 2 unit distance from the yz-plane.
>
>
> Any assistance would be greatly appreciated.
>
> from visual import *
> from time import sleep
>
> #create a set of axes for a visual reference when rotating
> xaxis=cylinder(pos=(0,0,0), axis=(5,0,0), color=(1,0,0), radius=0.2)
> yaxis=cylinder(pos=(0,0,0), axis=(0,5,0), color=(0,1,0), radius=0.2)
> zaxis=cylinder(pos=(0,0,0), axis=(0,0,5), color=(0,0,1), radius=0.2)
>
> #create the ball to be rotated
> ball = sphere(pos=(2,2,0), radius = 0.5)
>
> #set rotation angle for 1/20 of a rotation
> rotationAngle = 6.28/20.0
>
> #have the ball rotate about the x-axis while
> #maintaining 2 units from the xy-plane
>
> for i in range(20):
> ball.rotate(angle=rotationAngle, pos=(2,0,0), axis=(1,0,0))
>     sleep(0.2)
> thanks again,
>
> Mike
>
> -- 
> Michael Zittlow
> Mathematics Department Chairperson
> Southern Door High School
> Brussels, WI 54204
>
>
> ------------------------------------------------------------------------------
> Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and
> much more. Get web development skills now with LearnDevNow -
> 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts.
> SALE $99.99 this month only -- learn more at:
> http://p.sf.net/sfu/learnmore_122812
>
>
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users