Andy Ross <[EMAIL PROTECTED]> said: > Jim Wilson wrote: > > That's ok, but as I said earlier, the offsets that the viewer will > > use will be defined elsewhere because they are not necessarily the > > true actual pilot's eye point. > > We're evidently talking past each other. What you say is true. It is > *also* true that, under YASim, you have non-zero pilot offset numbers. > These are (1) defined by the FDM, in conflict with similar definitions > in the model, and (2) in an apparently different coordinate space from > the one the viewer is expecting. > > The viewer must be using those properties > (/sim/view/pilot/x-offset-m), no? How else would the settings by > YASim be affecting the view location? >
Ah ok. After I get done with the configurable viewer, those values won't be used by the viewer. You are correct we have been using them if they are set by Yasim. Under other flight models (eg JSBsim) the values defined in the xml are being used. When I get done those offsets will be in each view with xml and not in that path. If there is something that I need to use that comes from the FDM let me know what it is and how to use it. But I'm not going to be setting the eyepoint with FDM data (other than offseting it from the available origin value). Because, as I said before, the eyepoint is not necessarily the pilot's eye. > > Right now I believe the model's origin is being placed at the > > lon/lat/alt that is set by the FDM, converted to fg coordinates. > > This is correct, and exactly as it should be (so long as the FDM and > model agree on where the origin is, at the nose, for example). > It looks like most of the 3D models have the "origin" on the firewall. I think that is what JSBsim is using too. > > Note that this isn't taking center of gravity into consideration, so > > at some point we should be adding in an offset to cg too (or is > > lon/lat/alt at cg)? > > Eep, no. The FDMs already take the c.g. into consideration. If a > stopped aircraft rotates (about the c.g, of couse), you will see the > coordinate origin moving. We certainly don't want code outside the > FDMs to have to worry about this. The c.g. is an internal parameter > of the FDM. Other code might want to inspect it out of curiosity, but > we *certainly* don't want the view code worrying about rigid body > dynamics. :) > Well this might be useful to the 3D model. The effect probably isn't all that noticable compared to what we have now, but a real plane would pitch and roll about it's cg rather than the fixed "origin" as defined in a 3D model, wouldn't it? Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
