> FWIW, I still think the location should be configurable by the 3D > modeler in the FG xml files. FG would pass that info to the FDM and > it would return the appropriate position or FG would do the calcs > itself. The wind doesn't seem to be blowing that way, however ...
Actually, I thought of that too and it seems like a good idea. That is, that the 3D model "asks" for the lat/lon/alt of a specific point on the aircraft. This is probably the most configurable and versatile way to go. However ... which point does the FGFS side ask for the position of? I would assume they would ask for the point of origin of the 3D model (perhaps the nose, perhaps the firewall, perhaps the center of bounding box). When the FGFS side asks us (FDM) for a position, how do we know where that position lies in our frame of reference? When I think about this for long enough, I keep coming back to this: that if the nose is taken to be a common reference point between the FDM and the 3D model, then we (FDM) can simply provide the location of the Nose Reference Point (NRP) and the FGFS side can use that to properly place the vehicle. Now, the nose may not be the origin of the 3D model, but the NRP will be known relative to the 3D model origin. So, the FGFS side will be able to "bias" or "offset" the point we return and still place the model correctly in the scene. My $0.03. Jon
smime.p7s
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