Remote .vs Local IRIS Performer graphics

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Michael Jones (mtj++at++babar)
Wed, 27 Apr 1994 08:57:01 -0700

On Apr 25, 5:46pm, Timothy Cormier {76857} wrote:
> Subject:
:I am trying to understand why Onyx based Performer applications
:cannot pipe their display to an Indigo workstation. I have set
:the DISPLAY enviornment variable properly on the Onyx, and have
:set xhost on the Indigo to allow the pipe.

Because the graphics command stream generated by IRIS Performer
is sent directly to the graphics pipeline hardware attached to the
local workstation. IRIS Performer depends on such machine-tied
local events as vertical retrace interrupt signals and thus can not
work across a network.

:I have I heard about GL, OGL and now DGL! Can someone give me an
:explaination as to why I cannot display properly on another SGI
:machine.

You *can* display properly: X-class graphics across a network, and
high performance IRIS Performer applications on a local workstation.
There is just no way to send enough textured polygon definitions per
second across the network.

  x y z = 3 floats = 12 bytes
  r g b a = 4 floats = 16 bytes
  nx ny nz = 3 floats = 12 bytes
  s t = 2 floats = 8 bytes

 TOTAL = 48 bytes/vertex

  9000 tris/frame ++at++ 30Hz => 270000 triangles/sec:
    270000 x 3 x 48 = 38.88 mbytes/sec (bus speeds)

  231 tris/frame ++at++ 30Hz => 6944 triangles/sec:
   6944 x 3 x 48 = 0.999936 mbytes/sec (ethernet speeds)

Do you want to drive a 231-polygon display from your Onyx?

-- 


Be seeing you,      Phone:415.390.1455  Fax:415.390.2658 M/S:8L-590
Michael T. Jones    Silicon Graphics, Advanced Graphics Division
mtj++at++sgi.com         2011 N. Shoreline Blvd., Mtn. View, CA 94039-7311

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