On 8 Sep 2009, at 23:18, dave perry wrote:

> I don't think it is a good idea to go to a normalized value in a  
> blanket
> edit of other's instruments as the needle deflection in the animation
> SHOULD be scaled to achieve the 2 deg per dot for VOR and the 1/2  
> degree
> per dot for the LOC.  If the navradio.cxx maintains the 4x factor and
> clamps the heading-needle-deflection to +/- 10 deg, the modeler can  
> use
> the same scalar for both the VOR and LOC.  This scalar will likely  
> vary
> from instrument to instrument to get the propper dot performance.  +/-
> 0.7 is correct for the glide slope and again the scaling in the
> instrument will vary depending on the display.

Okay, there's some misunderstandings here:

- firstly I'm not changing the CDI deflection, which is [-10 .. 10]  
and will remain so, at all, for the reason you said - we have the 4x  
scale for localisers, and everyone is happy.
   (I might add the -norm version alongside, see point 3)

- secondly, I'm changing (or will) the glideslope deviation to be  
'correct' degrees: [-0.7 .. 0.7], i.e removing the spurious 5x scalar  
that has somehow crept in, and fixing many clients which assumed the  
range was [-10 .. 10], or something else again. This is in keeping  
with your flight instructor, I believe.

- thirdly, providing normalised properties *as well* *does* make sense  
for panel authors, because of how animations are typically built. As  
you point out, the actual physical movement - whether in arc of a  
electo-mechanical needle, pixels on a digital cockpit display, or  
whatever, is up to the panel. In practice, it's achieved with some  
kind of animation node, scaling the deflection property. For example:

        <animation>
         <type>translate</type>
         <object-name>GS-pointer</object-name>
         <property>instrumentation/nav/gs-needle-deflection-norm</ 
property>
         <interpolation>
             <entry><ind>-1.0</ind><dep>-0.0108</dep></entry>
             <entry><ind>1.0</ind><dep>0.0108</dep></entry>
         </interpolation>

        (from the b1900d)

Actually because of the clamped, normalised property, the entire table  
could go away, but that's another refinement. The point is the  
'0.0108' values are magic, and decided by the panel author - and I'm  
not going to touch them, for any panel (except to remove spurious 5x  
scaling factors). All I'm doing is simplifying the left hand-side of  
the interpolation table, which previously used to like

        <entry><ind>-10.0</ind><dep>-0.0108</dep></entry>
         <entry><ind>10.0</ind><dep>0.0108</dep></entry>

(actually it looked worse, due to the lack of clamping)

- fourthly, and most importantly, I'm not doing a blanket edit - I  
wish I could! I'm going to have to go through each aircraft, make the  
changes, and then test that aircraft. I'm sure I'l miss some things,  
but I still believe it's worth it to kill off the dreaded 5x  
multiplier, and fix all the aircraft who've been assuming the range is  
[-10..10] - or anything else.

Hopefully that's clearer.

James

------------------------------------------------------------------------------
Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day 
trial. Simplify your report design, integration and deployment - and focus on 
what you do best, core application coding. Discover what's new with 
Crystal Reports now.  http://p.sf.net/sfu/bobj-july
_______________________________________________
Flightgear-devel mailing list
Flightgear-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/flightgear-devel

Reply via email to