Thread: [Plib-users] plib, Scene Graphs and Demeter
Brought to you by:
sjbaker
Menu
▾
▴
plib-users
|
From: <mi...@st...> - 2002-03-23 03:58:35
|
I'm looking for a scene graph library to use with the Demeter terrain engine. One option is plib, using either its simple scene graph (ssg), or something like Open Scene Graph. How would these all work together? I'm sure I read somewhere that they could work together, with plib providing the OpenGL basics (i.e. window) and mouse and keyboard input, but how would I use ssg to insert and manipulate 3d modules? Thanks Mike <a href=http://www.stodge.net>stodge.net</a> - the powerhouse in personal commentary |
|
From: Steve B. <sjb...@ai...> - 2002-03-23 16:30:29
|
mi...@st... wrote: > > I'm looking for a scene graph library to use with the Demeter terrain engine. One > option is plib, using either its simple scene graph (ssg), or something like Open > Scene Graph. > > How would these all work together? I'm sure I read somewhere that they could work > together, with plib providing the OpenGL basics (i.e. window) and mouse and > keyboard input, but how would I use ssg to insert and manipulate 3d modules? PLIB doesn't cover window opening/resizing/whatever and it doesn't support mouse/keyboard input - most PLIB users use GLUT (or something similar) to do that. However, I think SSG would be a good library to help out with rendering whatever your terrain engine generates. SSG handles the nastiness of culling to the view frustum and optimising state changes - it also makes it easy to do things like adding man-made structures like buildings, bridges, etc by loading them from one of a dozen or so external file formats. Open Scene Graph is another reasonable choice for that - it has similar functionality to SSG but with a slightly different slant. SSG is focussed on realtime performance and also allows you fairly free access to OpenGL functionality. OpenSG is driven by a very strict view of 'correctness' and (as I'm told) doesn't perform as quickly as a result. It also doesn't allow you access to OpenGL with things like callback functions. If OpenSG doesn't provide everything you need, you are screwed - with SSG, it's usually possible to work around any limitations with callback functions or by deriving new classes from those that SSG provides. SSG is currently used by the FlightGear flight simulator - so you know it can render terrain nicely. Also, I come from a flight simulation background, so you can expect that my design for SSG is well suited to terrain rendering. OpenSG's main thrust has been towards the rendering of CAD models for the car industry and other similar applications. So, I believe that SSG would be a better choice than OpenSG. But of course I'm biassed. This is the wonderful world of OpenSource where projects like OpenSG and PLIB can co-exist and not feel the need to compete! There may well be specific features of OpenSG that you may need for your application that would make it a better choice than SSG. ----------------------------- Steve Baker ------------------------------- Mail : <sjb...@ai...> WorkMail: <sj...@li...> URLs : http://www.sjbaker.org http://plib.sf.net http://tuxaqfh.sf.net http://tuxkart.sf.net http://prettypoly.sf.net http://freeglut.sf.net http://toobular.sf.net http://lodestone.sf.net |
|
From: Mike S. <st...@sh...> - 2002-03-24 05:50:46
|
Steve, thanks for your very interesting reply. You made a very interesting point, regarding PLIB supporting terrain rendering. I have played around with the majik demo, and I was impressed. Have you tried incorporating the Demeter engine into PLIB? The beauty of Demeter for me is that it's essentially a "load-and-forget" library, taking just a few lines of code to load in and display terrain. Thanks again Mike On Friday 29 March 2002 9:50 am, Steve Baker wrote: > mi...@st... wrote: > > I'm looking for a scene graph library to use with the Demeter terrain > > engine. One option is plib, using either its simple scene graph (ssg), or > > something like Open Scene Graph. > > > > How would these all work together? I'm sure I read somewhere that they > > could work together, with plib providing the OpenGL basics (i.e. window) > > and mouse and keyboard input, but how would I use ssg to insert and > > manipulate 3d modules? > > PLIB doesn't cover window opening/resizing/whatever and it doesn't support > mouse/keyboard input - most PLIB users use GLUT (or something similar) to > do that. However, I think SSG would be a good library to help out with > rendering whatever your terrain engine generates. > > SSG handles the nastiness of culling to the view frustum and optimising > state changes - it also makes it easy to do things like adding man-made > structures like buildings, bridges, etc by loading them from one of a > dozen or so external file formats. > > Open Scene Graph is another reasonable choice for that - it has similar > functionality to SSG but with a slightly different slant. SSG is focussed > on realtime performance and also allows you fairly free access to OpenGL > functionality. OpenSG is driven by a very strict view of 'correctness' > and (as I'm told) doesn't perform as quickly as a result. It also doesn't > allow you access to OpenGL with things like callback functions. If OpenSG > doesn't provide everything you need, you are screwed - with SSG, it's > usually possible to work around any limitations with callback functions or > by deriving new classes from those that SSG provides. > > SSG is currently used by the FlightGear flight simulator - so you know it > can render terrain nicely. Also, I come from a flight simulation > background, so you can expect that my design for SSG is well suited to > terrain rendering. OpenSG's main thrust has been towards the rendering of > CAD models for the car industry and other similar applications. > > So, I believe that SSG would be a better choice than OpenSG. But of course > I'm biassed. This is the wonderful world of OpenSource where projects like > OpenSG and PLIB can co-exist and not feel the need to compete! There may > well be specific features of OpenSG that you may need for your application > that would make it a better choice than SSG. > > ----------------------------- Steve Baker ------------------------------- > Mail : <sjb...@ai...> WorkMail: <sj...@li...> > URLs : http://www.sjbaker.org > http://plib.sf.net http://tuxaqfh.sf.net http://tuxkart.sf.net > http://prettypoly.sf.net http://freeglut.sf.net > http://toobular.sf.net http://lodestone.sf.net > > _______________________________________________ > plib-users mailing list > pli...@li... > https://lists.sourceforge.net/lists/listinfo/plib-users |
|
From: Steve B. <sjb...@ai...> - 2002-03-24 06:13:07
|
Mike Stoddart wrote: > You made a very interesting point, regarding PLIB supporting terrain > rendering. I have played around with the majik demo, and I was impressed. That's a very quick hack just to show that it's possible. If you really want to be impressed, take a trip to www.flightgear.org and look at their screenshots. > Have you tried incorporating the Demeter engine into PLIB? No, I havn't. ----------------------------- Steve Baker ------------------------------- Mail : <sjb...@ai...> WorkMail: <sj...@li...> URLs : http://www.sjbaker.org http://plib.sf.net http://tuxaqfh.sf.net http://tuxkart.sf.net http://prettypoly.sf.net http://freeglut.sf.net http://toobular.sf.net http://lodestone.sf.net |
Thanks for helping keep SourceForge clean.
X