[Visualpython-users] Confusion about rotating camera around an object.

[Chris L. <chr...@sp...>]

I'm trying to rotate the camera around an object:

from visual import *

scene.background = (.6,.6,.6)


from visual import frame, cylinder


groundframe = frame()

g = cylinder(frame = groundframe, radius =10 , red = 0, blue = 0, axis = 
(0,0,-.1),opacity= .2)


from visual import frame, arrow, label

opacity = 0.1
shaftwidth = .005


axisframe = frame()
labelframe = frame()

xeaxis = arrow(frame = axisframe, shaftwidth = shaftwidth, 
axis=(10,0,0), color =(1,0,0),opacity = opacity) #  xe red
xwaxis = arrow(frame = axisframe, shaftwidth = shaftwidth, 
axis=(-10,0,0), color =(0,1,1),opacity = opacity) # xw  cyan
ynaxis = arrow(frame = axisframe, shaftwidth = shaftwidth, 
axis=(0,10,0), color =(0,1,0),opacity = opacity) # yn green
ysaxis = arrow(frame = axisframe, shaftwidth = shaftwidth, 
axis=(0,-10,0), color =(1,0,1),opacity = opacity) # ys magenta
zpaxis = arrow(frame = axisframe, axis=(0,0,1), color =(0,0,1),opacity = 
opacity)    # zp blue
zmaxis =arrow(frame = axisframe, axis=(0,0,-1), color =(1,1,0),opacity = 
opacity)    # zm yellow

nlabel = label(frame = labelframe, pos = ynaxis.axis, text = 'N',opacity 
= opacity)
elabel = label(frame = labelframe, pos = xeaxis.axis, text = 'E',opacity 
= opacity)
wlabel = label(frame = labelframe, pos = xwaxis.axis, text = 'W',opacity 
= opacity)
slabel = label(frame = labelframe, pos = ysaxis.axis, text = 'S',opacity 
= opacity)


scene.forward = (0,.7,-.6)



Gives me a view over the south axis towards the centre of the frame.
I want to rotate the camera so I can look over the E W and North axis 
but maintain the overall 'display' If I had a box drawn at 0,0,0 I would 
like to look at the four vertical faces inturn. by using the rotate command.

I am trying to use rotate to enact 3 buttons which act out the following 
three commands.

scene.forward = rotate( scene.forward, axis = (0,0,-1), angle = pi/2 )
scene.forward = rotate( scene.forward, axis = (0,0,-1), angle = pi )
scene.forward = rotate( scene.forward, axis = (0,0,-1), angle = (3 *pi)/2 )

i reckon I'm not really understanding up's effect on all this but i've 
got to the randomly poking in numbers which isn't having much useful effect.

I am trying to build an environment that i can rotate easily in 90 
degree chunks at the press of a command button but maintain the overall 
'appearance'. In essence so I view the scene from a similar elevation 
above the groundplane bu the position rotated appropriately round the 
centre point.






-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.409 / Virus Database: 268.15.18/584 - Release Date: 12/12/2006