[info] [croquet-user] External opengl applications integration

[Eugen Leitl]

----- Forwarded message from Joshua Gargus <schwa at fastmail.us> -----

From: Joshua Gargus <schwa at fastmail.us>
Date: Fri, 20 Apr 2007 11:15:21 -0700
To: croquet-user at duke.edu, Florent THIERY <fthiery at gmail.com>
Subject: Re: [croquet-user] External opengl applications integration
X-Mailer: Apple Mail (2.752.3)
Reply-To: croquet-user at duke.edu, Joshua Gargus <schwa at fastmail.us>

On Apr 20, 2007, at 7:19 AM, Florent THIERY wrote:

>Hello again
>
>I was wondering: is it conceptually feasible to cast opengl  
>applications within a croquet warp window? For now, it's only vnc- 
>like external app integration, right?
>
>Would be truely amazing for packetgarden or google earth,  
>especially if the transition is seamless, and if the collaborative  
>aspect is kept (ex: take your students with you into a google earth  
>portal, and teach them a history voice lesson using history layers).
>
>Why not, using video capture/streaming...

In general, is not feasible to embed an arbitrary 3D application such  
that each client has their own view (i.e. they can look around in  
whatever direction they want).  This is especially true if not every  
client has their own copy of the application.  However, even if  
everyone has the application, it is not necessarily possible.   
Leaving aside the OpenGL issues, there are serious issues around  
synchronizing the apps.  Taking the example of an embedded web- 
browser (non-VNC... each client has their own app)...

A user clicks on a link, which loads a new page.  They have a really  
fast machine with a fast net connection, so the page loads quickly,  
and they click on another link that appears.  Meanwhile, another user  
is still waiting for the first page to load when they receive the  
croquet-replicated click on the second link (which has not yet  
appeared).  Uh-oh, the applications are out of sync.  This is one  
example of how things *will* go wrong without very careful design for  
even a "simple" 2D application.

I won't even get started on the OpenGL issues that can arise  
(assuming that Google Earth even uses OpenGL on windows, and not  
Direct3D... but I digress even after saying that I wasn't going  
to :-); there are far too many of them.

Video-streaming is the only fool-proof approach to sharing 3D  
applications.  Real 3D sharing may be possible for a *specific*  
application (especially if you have the source code for that  
application), but a general framework that will work with any/most/ 
many out-of-the-box 3D applications is currently out of the question.

Josh

>
>Florent

----- End forwarded message -----
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Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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