On Fri, 17 Dec 2004 10:07:47 -0600
 "Curtis L. Olson" <[EMAIL PROTECTED]> wrote:

Jon, the problem is: how does the interface know how to normalize the control surface positions? Where does it read the maximum limits from? The FDM is really the only piece that is going to know this information.

This is **exactly** one of the big concerns I have. But, it cuts both ways. Using normalized position, NIETHER the FDM NOR the animation system knows where to place the elevator, for instance, unless two pieces of information are present. This is what I've been trying to illustrate for some time. For aerosurfaces, an absolute measurement makes sense (such as degrees or radians) for most aerosurfaces because it uniquely determines orientation. It is true that the FDM usually knows what the phyisical limits are for an aerosurface, but if we normalize the elevator or rudder setting we cannot simply pass the normalized value, we have to pass the limit as well. And I'm not prepared to continue to do this in the FDM proper. The presence of all the special purpose normalization routines is really confusing. Whatever is done will have to be done in the interface.

Additionally, what on earth are the animators using to turn normalized values into degrees, now? JSBSim is certainly not now passing in limit information. I suppose JSBSim defines one set of limits and - hopefully - the 3D modelers are using the same value. But, what if the limits are changed in the flight model?

One thing we could do is to simply define a NORMAL_FACTOR that corresponds to a constant, say 30 degrees. Then always normalize in the interface w.r.t. that.


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