pyopengl-users

[PyOpenGL-Users] scene graph examples?

[brett h. <bha...@ya...>]

Hi,

I could not find any examples using the scene graph nodes in openglcontext 2.0.  All of the
examples found in tests/ seem to only show how to use direct opengl calls.  None of the examples i
looked at showed how to work with the scene graph nodes.

How do i do something simple like: create a new group, transform, and model, and then render it?
I am expecting it would work something like...

from OpenGLContext.scenegraph.basenodes import *
BaseContext, MainFunction = testingcontext.getInteractive()

g = Group()
t = Transform()
geo = Box()

t.tranform(1,2,3)

g.addChildren(t)
t.addChildren(geo)

viewer = BaseContext
viewer.setSceneGraphData(g)
MainFunction(viewer)


-brett


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Re: [PyOpenGL-Users] scene graph examples?

[Mike C. F. <mcf...@ro...>]

Samples using scenegraphs (directly instantiated, not loading from a file):
    glelathe.py
    indexedfaceset_lit_npf.py
    indexedfaceset_lit_npv.py
    mouseover.py
    particles_simple.py
    point_and_click.py
    selectrendermode.py
    simplerotate.py
    wx_with_controls.py

Most of the tests are actually using scenegraph nodes, they just don't 
use the actual scenegraph *hierarchy*, as they are testing lower-level 
functionality.  OpenGLContext is strongly OO, it's not like VPython 
where you create "script" modules. You get things done by sub-classing 
the BaseContext (which is a class, not an instantiation of a class), 
then overriding methods such as OnInit and getSceneGraph.

Here's your expectation translated:

#! /usr/bin/env python
from OpenGLContext import testingcontext
BaseContext, MainFunction = testingcontext.getInteractive()
from OpenGLContext.scenegraph.basenodes import *

scene = sceneGraph(
    children = [
        Group(
            DEF = 'g',
            children = [
                Transform(
                    DEF = 't',
                    translation = ( 1,2,3 ),
                    children = [
                        Shape(
                            geometry = Box(),
                            # follows VRML97 standard, so normally
                            # want the material Node so that there
                            # will be lighting applied...
                            appearance=Appearance(
                                material = Material(),
                            ),
                        ),
                    ],
                ),
            ],
        ),
    ],
)
class TestContext( BaseContext ):
    def OnInit( self ):
        self.sg = scene
    def getSceneGraph( self ):
        return self.sg

if __name__ == "__main__":
    MainFunction ( TestContext)

I'll look at adding this kind of stuff to this page when I get a chance:
    http://pyopengl.sourceforge.net/context/vrml97.html
since it's likely the "right" place for it.

HTH,
Mike

brett hartshorn wrote:

>Hi,
>
>I could not find any examples using the scene graph nodes in openglcontext 2.0.  All of the
>examples found in tests/ seem to only show how to use direct opengl calls.  None of the examples i
>looked at showed how to work with the scene graph nodes.
>
>How do i do something simple like: create a new group, transform, and model, and then render it?
>I am expecting it would work something like...
>
>from OpenGLContext.scenegraph.basenodes import *
>BaseContext, MainFunction = testingcontext.getInteractive()
>
>g = Group()
>t = Transform()
>geo = Box()
>
>t.tranform(1,2,3)
>
>g.addChildren(t)
>t.addChildren(geo)
>
>viewer = BaseContext
>viewer.setSceneGraphData(g)
>MainFunction(viewer)
>
>
>-brett
>  
>
_______________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://members.rogers.com/mcfletch/

Re: [PyOpenGL-Users] scene graph examples?

[brett h. <bha...@ya...>]

Hi Mike,

Is there a way to build the scenegraph *hierarchy* in a cleaner way?
Your example has some crazy indentation going on.  It would be nice to have it more DOM like, ie:
node.appendChild(child)

thanks,
-brett

--- "Mike C. Fletcher" <mcf...@ro...> wrote:
> Samples using scenegraphs (directly instantiated, not loading from a file):
>     glelathe.py
>     indexedfaceset_lit_npf.py
>     indexedfaceset_lit_npv.py
>     mouseover.py
>     particles_simple.py
>     point_and_click.py
>     selectrendermode.py
>     simplerotate.py
>     wx_with_controls.py
> 
> Most of the tests are actually using scenegraph nodes, they just don't 
> use the actual scenegraph *hierarchy*, as they are testing lower-level 
> functionality.  OpenGLContext is strongly OO, it's not like VPython 
> where you create "script" modules. You get things done by sub-classing 
> the BaseContext (which is a class, not an instantiation of a class), 
> then overriding methods such as OnInit and getSceneGraph.
> 
> Here's your expectation translated:
> 
> #! /usr/bin/env python
> from OpenGLContext import testingcontext
> BaseContext, MainFunction = testingcontext.getInteractive()
> from OpenGLContext.scenegraph.basenodes import *
> 
> scene = sceneGraph(
>     children = [
>         Group(
>             DEF = 'g',
>             children = [
>                 Transform(
>                     DEF = 't',
>                     translation = ( 1,2,3 ),
>                     children = [
>                         Shape(
>                             geometry = Box(),
>                             # follows VRML97 standard, so normally
>                             # want the material Node so that there
>                             # will be lighting applied...
>                             appearance=Appearance(
>                                 material = Material(),
>                             ),
>                         ),
>                     ],
>                 ),
>             ],
>         ),
>     ],
> )
> class TestContext( BaseContext ):
>     def OnInit( self ):
>         self.sg = scene
>     def getSceneGraph( self ):
>         return self.sg
> 
> if __name__ == "__main__":
>     MainFunction ( TestContext)
> 
> I'll look at adding this kind of stuff to this page when I get a chance:
>     http://pyopengl.sourceforge.net/context/vrml97.html
> since it's likely the "right" place for it.
> 
> HTH,
> Mike
> 
> brett hartshorn wrote:
> 
> >Hi,
> >
> >I could not find any examples using the scene graph nodes in openglcontext 2.0.  All of the
> >examples found in tests/ seem to only show how to use direct opengl calls.  None of the
> examples i
> >looked at showed how to work with the scene graph nodes.
> >
> >How do i do something simple like: create a new group, transform, and model, and then render
> it?
> >I am expecting it would work something like...
> >
> >from OpenGLContext.scenegraph.basenodes import *
> >BaseContext, MainFunction = testingcontext.getInteractive()
> >
> >g = Group()
> >t = Transform()
> >geo = Box()
> >
> >t.tranform(1,2,3)
> >
> >g.addChildren(t)
> >t.addChildren(geo)
> >
> >viewer = BaseContext
> >viewer.setSceneGraphData(g)
> >MainFunction(viewer)
> >
> >
> >-brett
> >  
> >
> _______________________________________
>   Mike C. Fletcher
>   Designer, VR Plumber, Coder
>   http://members.rogers.com/mcfletch/
> 
> 


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Re: [PyOpenGL-Users] scene graph examples?

[Mike C. F. <mcf...@ro...>]

Sure, append to the children...

    t.children.append( someShape )

HTH,
Mike

brett hartshorn wrote:

>Hi Mike,
>
>Is there a way to build the scenegraph *hierarchy* in a cleaner way?
>Your example has some crazy indentation going on.  It would be nice to have it more DOM like, ie:
>node.appendChild(child)
>
>thanks,
>-brett
>  
>
_______________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://members.rogers.com/mcfletch/