Re: [Visualpython-users] Control camera zoom?

SourceForge Headquarters 1320 Columbia Street Suite 310 San Diego, CA 92101 +1 (858) 422-6466

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta content="text/html;charset=windows-1252"
 http-equiv="Content-Type">
  <title></title>
</head>
<body bgcolor="#ffffff" text="#000000">
Craig Berry wrote:
<blockquote
 cite="mid:8de...@ma..."
 type="cite">
  <pre wrap="">On Wed, Feb 3, 2010 at 14:49, Craig Berry <a class="moz-txt-link-rfc2396E" href="mailto:cd...@gm...">&lt;cd...@gm...&gt;</a> wrote:
  </pre>
  <blockquote type="cite">
    <pre wrap="">On Wed, Feb 3, 2010 at 13:53, Bruce Sherwood <a class="moz-txt-link-rfc2396E" href="mailto:Bru...@nc...">&lt;Bru...@nc...&gt;</a> wrote:
    </pre>
    <blockquote type="cite">
      <pre wrap="">Could you describe briefly what it is that you want to do?
      </pre>
    </blockquote>
    <pre wrap="">I want to allow the user to control the camera with middle- and
right-drag mouse gestures, but also, if they click on an object, slew
the camera to point at that object from a particular distance.  I can
slew the camera's aim point by changing scene.center, but I'm having
the difficulties described previously with putting it at a particular
(apparent) distance from the selected object.
    </pre>
  </blockquote>
  <pre wrap=""><!---->
So...anybody have a clue on how to do that elegantly?

</pre>
</blockquote>
Hi there, 
    I don't know if this program is elegant or not but it does give you
control over Range, Center and Forward. 
It also enables you to defines the Range upper and lower boundaries. 
This requires that Userzoom be turned off and scene.range driven
directly. 
 
A Feedback loop is setup between scene.range and scene.mouse.pos that
drives the zoom effect. 
Careful positioning of the mouse pointer gives you more control. 
 
 
''Simple zoom routine GNU \xa9 Symion MMX 
 
"r" will Reset the scene range, scene.center and scene.forward 
 
Middle Mouse key and drag will Zoom 
Hint: 
    Find the spot (any corner) and draw mouse with middle key pressed 
    toward the scene center and back to the corner! 
 
Right Mouse key will Spin 
Left Mouse key will change scene.center 
 
"x" will exit 
''' 
 
from visual import * 
 
userzoom = False 
nexit = False 
scene.userzoom = userzoom 
scene.autoscale = False 
srange = 10.0 
scene.range = srange 
rangemin = 1.0 
rangemax = 100.0 
scenter = vector(scene.center) 
forward = vector(scene.forward) 
 
col = (0,1,0) 
work = list() 
work.append(sphere(color=col)) 
work.append(box(pos=(1,0,0),color=(1,0,0))) 
scene.visible = True 
print __doc__ 
while not nexit: 
    post = scene.mouse.pos 
    if scene.kb.keys&gt;0: 
        km = scene.kb.getkey() 
        if km == 'x': 
            nexit = True 
        elif km == 'r': 
            srange = 10.0 
            scene.range = srange 
            scenter = vector(0,0,0) 
            scene.center = scenter 
            scene.forward = forward 
    elif scene.mouse.events&gt;0: 
        mk = scene.mouse.getevent() 
        if mk.drop == 'middle': 
            userzoom = False 
            print 'Zoom Off: %s' %(srange) 
        elif mk.drag == 'middle': 
            userzoom = True 
            print 'Zoom On: %s' %(srange) 
        elif mk.press == 'left': 
            if mk.pick: 
                post = vector(mk.pick.pos) 
            scene.center = scenter = post 
            print 'Center %s' %(scenter) 
    if userzoom: 
        # print 'range (%0.3f,%0.3f,%0.3f) = %s'
%(post.x,post.y,post.z,mag(post)) 
        # Limit zoom! This line controls the Entire process 
        srange = min(rangemax,max(rangemin,mag(post))) 
        scene.range = srange 
 
for thing in work: 
    thing.visible = False 
del work 
scene.visible = False 
 
 
Symion 
</body>
</html>

Re: [Visualpython-users] Control camera zoom?

This project is no longer active. See vpython.org.

Re: [Visualpython-users] Control camera zoom?