Gamble, Murray - Kan AV HFE (gamblem++at++kan.marconi.ca)
Tue, 26 Oct 1999 11:03:00 -0700 (PDT)
Although it does not make use of Performer, it sounds to me like VAPS may
be a tool worth having a look at. We use VAPS extensively for visual
simulation of flight instruments as well as for prototyping of tactical
displays, etc. VAPS provides a WYSIWYG drawing iterface for defining the
visual characteristics as well as the behaviour of your display elements
(i.e. dial, tape, ADI, etc.) and allows you generate C code that can be
compiled on a number of platforms. Performance is impressive - product
is a little pricy. Check it out at http://www.virtualprototypes.ca.
P.S. I have no affiliation with Virtual Prototypes. I'm just a happy
customer!
Cheers,
Murray.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Murray G. Gamble, B.Eng
Human Factors Engineering - Aerospace
Marconi Canada
Kanata, Ontario, CANADA
-----Original Message-----
From: guest [SMTP:guest++at++holodeck.engr.sgi.com]
Sent: 25-Oct-99 4:59 PM
To: info-performer; info-multigen
Cc: Chris Slominski
Subject: 2D/3D flight instrument displays
I have a question on how best to implement flight instrument displays
using
Performer for a real-time flight simulator.
The end system will have several display panels driven from an Onyx2.
For
example, one display for the artificial horizon, one display for the mode
control panel, throttle display, and several displays for the pilots out
of
the cockpit views. This will be a very graphics intensive system where
every polygon counts.
So it seems to me that I have two options for creating flight
instruments.
Option 1)
I have Multigen II and it has an instrumentation package where you can
generate open flight models of flight instruments easily. I can create
the
instruments in Multigen and then in Performer put them into the scene
graph
for rendering. The only problem is that the instruments are treated as
3D
objects and through the scene graph must go through all the culling and
transformations that other 3D objects require. But the flight
instruments
do not require all the transformations and culling calculations, and it
seems a waste to do all the extra calculation when they not required.
Option 2)
I could use openGL directly from inside the draw process and therefore
directly control what calculations are performed on my instruments. This
seems performance wise to be the better choice. But if I go this route I
lose all the nice functionality of the Multigen and the scene graph. And
as
a consequence my code becomes more complex and more difficult to write.
So the question is, is it worth the extra programming complexity to save
on
the polygon count and to save on the unnecessary calculations on the
instruments by using openGL as opposed to using open flight and the scene
graph? How much will putting the open flight instruments in the scene
graph
negatively affect performance?
I am sure that someone out there has written a flight simulation
application
using Performer. How did you implement your flight instruments?
Do you'all have any suggestions, comments?
Thanks for you help.
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