openvrml-develop

[openvrml-develop] Problem rendering from one browser into multiple/changing openvrml::gl::viewers

[<MSo...@ya...>]

Hi,

I am using OpenVRML to render VRML scenes among other things into an
GL context. This is fairly straight forward with an overloaded
openvrml::gl::viewer that overlaods funcions like initialization and
view port setting with empty or cut down functions and works pretty
well. My only problem is, that my app has multiple windows with each
having its own GL context, and I want to draw one scene in multiple of
these windows. OpenVRML seems to remember a lot of the GL context it
used first in its scene node structures. E.g. for speeeding things up
OpenVRML uses GL-lists to save objects into the GL context and later
uses the GL list ID to render the object. The GL list id is stored in
the scene node structure in OpenVRML. Of course such a list id is only
valid in one GL-context which has the effect that all other contexts
either draw nothing or some incredible mess (depending on what is in
the lists with these IDs in the other contexts). I tried hacking this
by overloading the views begin_object / end_object function with
something that returns 0 without building up a GL list, but this
doesn't work either. There seems to be more information from the GL
context stored in the scene structures, I didn't identify yet.

Is there some intended way to get around this or am I doing something
fundamentaly wrong by assuming that one browser/scene can be reused
for different views?

When I am using one browser per view and never switch the view of a
browser, everything works fine, but this isn't a good solution.

Best regards,

Michael

-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.375 / Virus Database: 267.14.21/236 - Release Date:
20.01.2006
 


	

	
		
___________________________________________________________ 
Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de

Re: [openvrml-develop] Problem rendering from one browser into multiple/changing openvrml::gl::viewers

[Braden M. <br...@en...>]

On Sat, 2006-01-21 at 17:25 +0100, Michael Sögtrop wrote:
> Hi,
> 
> I am using OpenVRML to render VRML scenes among other things into an
> GL context. This is fairly straight forward with an overloaded
> openvrml::gl::viewer that overlaods funcions like initialization and
> view port setting with empty or cut down functions and works pretty
> well. My only problem is, that my app has multiple windows with each
> having its own GL context, and I want to draw one scene in multiple of
> these windows. OpenVRML seems to remember a lot of the GL context it
> used first in its scene node structures.

[snip]

> Is there some intended way to get around this or am I doing something
> fundamentaly wrong by assuming that one browser/scene can be reused
> for different views?

Unfortunately its simply not supported. It's something I'd like to
support; but as you've discovered, the library basically assumes a 1:1
relationship between a browser and a viewer.

> When I am using one browser per view and never switch the view of a
> browser, everything works fine, but this isn't a good solution.

I'd welcome a patch to fix the library to support this; however, it's a
nontrivial amount of work.

-- 
Braden McDaniel                           e-mail: <br...@en...>
<http://endoframe.com>                    Jabber: <br...@ja...>