evans@mhuxt.UUCP (crandall) (09/01/85)
Have there been any developments in flight simulators that fall between MS flight simulators that run on PCs and things like the formidable packages from the likes of Evans & Sutherland? I have seen pictures from a Silicon Grpahics demo that looked pretty good, but did it model flight well? With the price/performance ratio of hardware improving so rapidly at some point it should be possible to add a stick and rudder pedals to a powerful home machine and get something out of it. Any comments on what is minimal hard- ware --- is an Amiga with its graphics hardware in the ballpark? Steve Crandall ihnp4!mhuxt!evans
lmiller@ucla-cs.UUCP (09/02/85)
In article <1112@mhuxt.UUCP> evans@mhuxt.UUCP (crandall) writes: >Have there been any developments in flight simulators... >Any comments on what is minimal hardware-- >is an Amiga with its graphics hardware in the ballpark? During the past 18 months we have been building/writing flight simulators using IRIS terminals and workstations, primarily for investigating pilot- aircraft interfaces and expert systems for aircraft and pilot performance. We've added joysticks, throttles, voice I/O, and lots of tools for rapidly interacting with the display tables. The screen resolution is 767x1023, 12 bits per pixel, double buffered (leaving 6 per swappable image, less 2 reserved for certain background images, or 16 colors on the screen at any one time). This number of colors is marginally adequate. The resolution is fine. We do a substantial amount of non-graphics calculations per display loop, so we're updating the image between 5 and 10 times per second--not quite adequate for smooth motion. Ten updates per second is the minimum you'd want. Obviously, we do lots of tricks to get as much speed as possible, but other issues are more important now. We designed and built our own joystick/throttle and interfaces, using one of the RS-232 ports on the IRIS. Our joystick is a 9600 baud ASCII device that sends its x, y and throttle values (using A to D's and an 8008) when queried by the program. The joystick itself was obtained from a used aircraft parts shop, but there are new ones with all the A/D's built in that are not very expensive. Or you can go to McFadden controls and get real simulator hydraulics for 50K each. Plus an oil change every 1,000 hours. You will tire of slow, low resolution, poorly modelled flight quickly. An IRIS or equivalent (raster tech, chromatics, etc.) with fast graphics computing is the minimum you will want. There is still lots of other computations needed. The IRIS workstations are in the 40-60 K region, as I recall. Aerodynamic simulations can be reasonable with only very simple models. It is not necessary to model all the flow equations, since they turn out to be inaccurate anyhow, and it is the solutions you want. For special circumstances, such as ground effect, simple heuristics are best. By the way, we are interested in hearing from experienced UNIX/C programmers, with extensive graphics background, who also have a pilot's license. The work is being done at ISI. L. Miller {lmiller@isi-hobgoblin or lmiller@ucla-locus}
dave@onfcanim.UUCP (Dave Martindale) (09/05/85)
The IRIS is indeed a nice graphics engine. SGI supplies a flight simulator demo program with it; it's pretty awful trying to use a mouse as a stick and mouse buttons as rudder. (Particularly when the rudder is simulated wrong). You can buy 24 bits/pixel for the IRIS, giving lots of colours per image even in double-buffered mode. The 6-bit limitation referred to by another other can be overcome simply by giving SGI more money. There is also a "dogfight" version of the simulator, where several people "fly" on several workstations, and they each broadcast their positions many times per second to the other stations. You can see, and shoot at, the other planes. Lots more fun than video games. The current hardware does about 15 or 16 updates per second of the flight simulator, dropping to about 12 for the dogfight. But SGI was showing a 68020 processor upgrade at SIGGRAPH that would do 20 updates/second. Very nice. Since the drawing is double-buffered, you don't see incomplete images being drawn. And since the screen is 60Hz refresh non-interlaced, there is no flicker.
thomas@utah-gr.UUCP (Spencer W. Thomas) (09/26/85)
In article <14683@onfcanim.UUCP> dave@onfcanim.UUCP (Dave Martindale) writes: >The IRIS is indeed a nice graphics engine. SGI supplies a flight simulator > >The current hardware does about 15 or 16 updates per second of the >flight simulator, dropping to about 12 for the dogfight. But SGI was >showing a 68020 processor upgrade at SIGGRAPH that would do 20 updates/second. Interestingly enough, (rumor follows) they had to install a "governer" in the 68020 version. Otherwise, it would compute updates too quickly, leading to situations in which the airplane was essentially uncontrollable. -- =Spencer ({ihnp4,decvax}!utah-cs!thomas, thomas@utah-cs.ARPA) "The difference between reality and unreality is that reality has so little to recommend it." -- Allan Sherman