Hi,
--- Tim Moore <[EMAIL PROTECTED]> schrieb: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Christian Mayer wrote: > > Josh Babcock schrieb: > >> LeeE wrote: > >>> On Sunday 30 December 2007 09:47, Detlef Faber > wrote: > >>>> Hello, > >>> Could it be that the overhead of rotating many > simple billboard > >>> objects accounts for the performance hit over an > equivalent number > >>> of more complex static models? > That does have significant overhead as it is all > done on the CPU > >> Probably has more to do with the fact that the > billboards are not only > >> UV mapped, but also have an alpha channel. These > new ones appear to just > >> be using OGL materials. I wonder, does OSG do > vertex painting? That > >> would be a great way to make these look better > without adding a texture. > There should be no problem with using textures for > the trees on any hardware > manufactured after the early part of this century. > In the OSG world we will have to > take some care that the trees are not depth-sorted > as that will be quite expensive with > high tree densities. > > > > I'm a bit out of the current 3D programming that > FGFS uses... But > > wouldn't a vertex shader help in this case (for > billboarding as well as > > generic trees)? > > > They would help with a lot of things with respect to > trees: > * you could do the billboarding in a shader, as you > mention; > * there's a trick in OpenGL that is demonstrated in > the OSG osgforest demo that uses a > shader to create very cheap tree "instances" that > don't incur the cost of matrix > transform for each tree; > * everything else you can do with shaders to make > things look good. > > I would think that we would punt the billboarding if > we can come up with a cheap 3D tree > that is convincing from the air. > > I changed the subject because we currently have no > way to specify shaders other than > to hard-code them in the C++ code. In general, the > parameters we specify for materials > are quite limited. I've been studying the Ogre > (www.ogre3d.org) materials system for > a while and think that the syntax of their material > scripts system, www.ogre3d.org/docs/manual/ , > adapted to XML property lists and FlightGear needs, > would be quite excellent. > It seems quite exotic from a FlightGear point of > view, but we will soon have shadows > and multi-pass lighting (for landing lights) and we > will need some way for materials > to interact with them. > > CU, > > Christian > > Tim your idea sounds good - that would maybe improve other things in FGFS graphic too: water (ocean...), runways and of course the objects ( building and airrafts) But back too the forest and trees: are imposters are possible way too, to get a good perfomance and looking? Regards HHS still in work: http://www.hoerbird.net/galerie.html But already done: http://www.hoerbird.net/reisen.html Jetzt Mails schnell in einem Vorschaufenster überfliegen. Dies und viel mehr bietet das neue Yahoo! Mail - www.yahoo.de/mail ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
