Le Mon, 28 Dec 2009 19:11:40 +0100, Paul Martz <[email protected]> a écrit:
Hi Sukender -- First, OpenGL doesn't really have a default coordinate system (see the thread "Cameras View Matrix - I am perplexed" from October). osgGA camera manipulators use a right-handed +z up convention for the home position, but this is easily configured to anything else by the app if desired. Also, OSG apps don't have to use osgGA manipulators, they can use their own. So although osgGA has a default, I'd argue it's incorrect for any code to make assumptions about an OSG app's coordinate system. Regarding OSG plugins, I think their primary job is to either give me what they read, or write out what I give them. If I modeled an aircraft with the nose pointing in +y, then I expect the OSG plugin to give me a scene graph with the nose pointing in +y. If it doesn't do this by default, that's a bug, isn't it? That being said, I don't object to OSG plugins having Options to control application of transformations. In fact, this is required in some cases. For example, OpenFlight DOF nodes specify range of motion parameters, and the plugin must scale and rotate these values to match the app's coordinate system. Paul Martz Skew Matrix Software LLC _http://www.skew-matrix.com_ <http://www.skew-matrix.com/> +1 303 859 9466 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Hi Paul, What I like with you is that your answers are clear! ;) Well you're absolutely right. Thanks. The only thing that bothers me is: should "write( read(A) ) == A"? As far as I'm concerned, I would answer "yes". And you? This is not the case when reading FBX and writing, for instance (regardless of the output format). So I've been scratching my head to figure out where the problem (bug?) is, and I still don't find a suitable answer. Maybe something stupid I don't see in my code... Cheers, -- Sukender PVLE - Lightweight cross-platform game engine - http://pvle.sourceforge.net/ _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
