🚀 go-pugleaf

In article <1993Jan20.190707.28040@aio.jsc.nasa.gov>, mancus@carla.jsc.nasa.gov writes:
> 
>   We are presently attempted to develop a real-time application
> that must run at a 30 Hz graphical update rate.  We are finding
> that a serious slowdown occurs when the displayed models are too
> large to fit in the display window.  As soon as ANY clipping occurs,
> we lose as much as 10 Hz!  (Test case: 3000 polygon flat-shaded
> sphere, no tmeshes, monocolored, 340VGX, no accumulation buffer,
> window is 1024x768.  The final product will run on a RealityEngine,
> CPU unspecified.)
>   What can we do to avoid this speed hit?  Our simulation will
> have to show polygons that are cut by the window borders, but
> we just can't live with this kind of penalty.  Are there GL
> calls we are omitting?
> 
> -- 
> | Keith Mancus    <mancus@cheers.jsc.nasa.gov>                           |
> |                 N5WVR                                                  |
> | "Money is never *mere*.  It separates the feasible                     |
> |    from the infeasible."                                               |

   Clipping does require work. It can slow you down. However, the Reality
Engine was engineered to handle this problem. You should benchmark your
app on a RealityEngine before you get too worried. Secondly, there is
some work afoot which allows spheres to be drawn extremely quickly on
a RealityEngine. You might try e-mailing srf@sgi.com with questions about
spheres on RealityEngine.

john m. airey      airey@asd.sgi.com  (415) 390-5248
                   M/S 7U-553 Silicon Graphics, Advanced Graphics Division
                   2011 N. Shoreline Blvd., Mtn. View, CA 94039