Thorsten wrote: > -----Original Message----- > From: Renk Thorsten [mailto:thorsten.i.r...@jyu.fi] > Sent: 21 February 2013 06:54 > To: FlightGear developers discussions > Subject: Re: [Flightgear-devel] Low visibility issues > > Vivian: > > > There seem to be significant issues with the loading of terrain. If we > > load too much, the frame rate drops, if we load too little it looks > > poor, and AG radar doesn't work. Actually. We don't load enough for AG > > radar to work realistically in any case. We probably need something > > between 50 and 100 k for this , and we're unlikely to accommodate the > > memory requirements of this, at least for 32 bit systems. > > James: > > > a) is a trivial fix in the tile-manager, I think, and seems reasonable > > to me. The only issue will be setting a sensible minimum size, since I > > assume some people are brining the visibility down to reduce number of > > tiles loaded, and hence RAM use / frame-rate. > > Okay, here are some experimental facts on my old 32bit system. I had a > GeForce 8600M and 4 GB of memory with a 32bit Linux installation. With this > setup, without using random vegetation and random buildings, I could > render terrain with 250 km visibility range (I patched the binary for that > purpose, otherwise it gets clipped at 120 km) without any problems in > default scenery. I could easily do 120 km in custom scenery, and even with > vegetation and buildings on 55 km were quite safe in custom scenery. So it's > not true that fixing a minimum visibility of 20 km we'd run into 32bi memory > issues. > > As for framerate, I'd guess that GPUs which are so old that they have real > issues processing the vertex count of 20 km scenery fast enough are hit also > hard by the fragment shader - but fragment shader load is independent of > the visibility range. > > There are lots of forum users who have issues with low framerate - about > anything (no random vegetation, no shaders, no random buildings, no > complex planes, no AI traffic, no 3d clouds...) seems to help more than to get > visibility down. I'm not aware of any single user who uses less than 20 km > visibility because the framerate is not acceptable otherwise, and I have never > seen anyone suggest this to users. Since vertex count goes quadratically in > visibility, it matters a lot if you use 50 or 120 km, but not so much if you use 10 > or 20. > > Nevertheless, at some point my suggestion would be to create a > commandline-enabled legacy mode for really old hardware which gives you > access to a minimal setup in which terrain radars, Advanced Weather &Co > are disabled, but define the default setup of FG in such a way that terrain > interaction based stuff can make assumption about how much terrain is > loaded. For a halfway decent system, 20 km should not be any problem if I > could run 250 km on a 5-year old laptop, and I think we can at some point > make that default assumption and have a fallback option in case it doesn't > work. >
I was not referring to a frame rate issue, but FG running out of memory. http://www.flightgear.org/forums/viewtopic.php?f=5&t=18913&p=177392#p177392 It is rare to see that happening using the current scenery, but here if I select random buildings and objects with a high value for trees, I can get Win32 to run out of memory. Apparently at least one other user has a problem. Vivian ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
