On Wed, 15 Dec 2004 10:41:27 -0500
 "Norman Vine" <[EMAIL PROTECTED]> wrote:

Jim Wilson writes:

And the Simgear 3D animation code is all about taking those normalized values
and translating them to a representation of degrees movement. On the surface,
this doesn't make sense to me either.

I can think of no other generalized expression of a 'control's state' whether it be rotation, fluid pressure, amps what ever :-)

Once you start specializing there is no end and IMO using the
Normalized Values makes perfect sense for the abstract Control Module.

Simple translators from Normallized to Actual value are all that is needed
and are already instantiated on the FGFS side. Client applications such
a JSBSim can easily implement wrappers when talking to FGFS

Your example is irrelevant. Fluid pressure cannot be seen. Amps cannot be seen. Neither Amps nor fluid pressure are reported on a zero to one scale. Aerosurfaces can be drawn and seen, and that's not done on a zero to one basis either. Like I said, there are some things that can be done on a zero to one basis, such as landing gear deployment. But, aerosurfaces are reported in degrees, regardless of whatever aircraft it is, it's already "generalized" to its lowest common denominator. Why it should be further "reduced" and then reassembled to the exact same value (one hopes) later on when rendered via SimGear - that's defies description, IMHO.

It is true that we can pollute our code (a.k.a. "implement wrappers") to satisfy FlightGear, but why? We know what the control surface limits are. So, what do we do? Pass a normalized value AND the aerosurface limits so they can be reconstructed later? Why not just pass the raw value and be done with it?

Code that massages physical parameters to make up for shortcomings in the rendering/animation system doesn't belong in the FDM. If it doesn't belong in SimGear or on the FlightGear side, it belongs in the FGInterface class - but I don't think it even belongs there.

I know this sounds "forceful", and I don't mean to step on any toes here, I just feel strongly about this.


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