David Megginson <[EMAIL PROTECTED]> said: > Lee Elliott writes: > > > Is there any way to set a constriant on it? It's fine when it's > > smoothing angles > 90deg < 270 but it would be better if it didn't > > try to do sharper angles. This seems to be the cause of the > > artifacts often seen on models, for example at the wing traiing > > edges. > > It's a bit of a mess, really. The problem is that AC3D is (or was, > until recently) the only general format that worked fully with plib, > but AC3D files do not contain information on normals. If there's a > better semi-standard format that we can use -- one that we can easily > get From AC3D and Blender and import into plib with object names, > normals, and texture information intact -- I'll be happy to switch to > it.
A lot (but not all) of the mess we've seen has to do with bad modeling work. I know because I've done the worse of it. With the normals being generated on the fly the right way to construct the model is with surfaces assigned to separate objects if they are sharpy edged, like the ailerons. While there are certain advantages to other methods (with greater control over the normals), this ac3d method really isn't difficult to do at all. If we further developed the ac3d loader for our purposes we might solve most of the problems. Much of the annoying issues with ac3d loading has to do with the optimization step. I feel that if we copied this loader code into SimGear and interact with plib at a lower level on this, we could eliminate some of the things that don't help us, and add to it some features that would help us. It'd be nice to have the ability to substitute textures for example. Plus we might be able to track our own table of loaded textures so that their use can be optimized. We may also be able to implement some of our own extensions and certainly could probably look at implementing some of the ac3d features that aren't currently supported in the plib loader (like selected flat shading for things that really are square edged!). Having a VRML1 loader would be useful. It would be great to move to something so widely supported, but I think we should still develop our own laoder and have it oriented toward loading and supporting simulation models without worrying about fitting in with the plib development goals. Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
