----- Original Message ----- From: "Frederic Bouvier" <[EMAIL PROTECTED]> To: "FlightGear developers discussions" <[EMAIL PROTECTED]> Sent: Sunday, October 17, 2004 4:38 AM Subject: Re: [Flightgear-devel] VBOs - performance test results
> James Turner a �crit : > > > > > On 17 Oct 2004, at 10:15, Erik Hofman wrote: > > > >>> Before other people think "WOW, FG could run 60% faster!!!", please > >>> keep in > >>> mind that an application like FG can't do everything just by using > >>> VBOs and DLists. > >> > >> > >> For what it's worth, experts keep telling me the display lists are > >> always faster than VBO's anyhow. The advantage of VBO's comes when > >> you want to use non-static data like morphing. > >> > >> That and the fact that all drivers seem to support display lists at > >> the moment make me believe we should stick to display lists a little > >> longer. > > > > > > That sounds totally incorrect as I understand it. VBOs are essentially > > the same ideas as vertex arrays, but with more control over which > > memory they are located in (system, AGP or GPU) and with how they will > > be updated. They can be used for 'streamed' vertex data such as > > skeletal animation and morphing (by specifying that they should not be > > GPU resident) but for FG the benefit (which should be large) would > > come from placing each tile (or other large data set) and mesh onto > > the GPU as a fixed, resident VBO. > > You are wrong here as long as FG will use state changes ( read different > textures ) to represent terrain property ( forrest, crop, urban ). You > can't put state changes in a VBO, so you end up with multiple, small > VBOs that is worst than display lists. Frederic! I must admit that you are absolutly right with Dlists I got 107 fps and only 78 fps w/ VBO on 5950Ultra It's w/o shaders. I make additional test And tell results with shaders. > > That could be different with another terrain engine that would drape a > single, large and unique texture on a single tile made with a single > geometry object. > > People arguing for VBOs are always forgetting this reality. > > -Fred > > > > _______________________________________________ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > 2f585eeea02e2c79d7b1d8c4963bae2d > _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
