> From: "Alberico, James F" > > Hi, > > I'm trying to track down how I can attach a view to another object in > the sim, particularly for a multiplayer aircraft other than the ownship. > I would like to switch to the viewpoint of each of the "other guys" in > the virtual world. > > As documented at http://flightgear.org/Docs/fgfs-viewer-howto.html : > > -------- > Syntax for the eye position is: > <from-model type="bool">true or false</from-model> > <from-model-idx type="int">modelnumber</from-model-idx> > Syntax for the target or at position used in views of type "lookat" is: > <at-model type="bool">true or false</at-model> > <at-model-idx type="int">modelnumber</at-model-idx> > --------- > > But I can't find out where the "modelnumber" comes from, or what it > really means. All the examples use zero, so I've assumed that was the > ownship. > > I've looked through the code and docs, and searched many of the > mailing-list archives, but haven't found any examples or explanations > yet. A idea of how to use this for "models" in general, followed by > understanding the implications and current capabilities for multiplayer > "otherships" would be great. > > Any help would be appreciated, even references to archived discussions. > Thanks! >
The model number was originally a concept which was thought to provide a hook for accessing the location of a particular model. Basically, it would internally end up going back to the FGLocation object for a particular model in order to reference it's position and orientation data. This would be set up by the model manager, be reserved for just aircraft models, and would provide a method of accessing models as an array of objects, similar to how the view manager sets up views. AFAIK this has not been implemented. The AI models, the scenery model work, the 3D cockpit, aircraft model work has involved a few developers and even so it is very well organized. It probably wouldn't actually take much to index the aircraft models and allow a view mode that rotates through a dynamically modified list of views which are sourced at the location of multiple models (without having to set each view up individually in preferences.xml). Some modifications to the code would be required. Without that happening, or happening right away, you can still acheive something similar by setting up additional views in preferences.xml. If you look at the "Look From" Tower in preferences.xml you'll see clearly how you can reference position and orientation values from anywhere in the property tree. And if I remember this code correctly, you can probably modify these "property paths" on the fly. For example if you had a nasal script that changes the string value in "/config/eye-alt-ft-path" then in fact the source property of the altitude of the view would change, next time the view manager class updates (every frame). Look especially at the update function in the viewmgr.cxx file in FlightGear/src/Main. Hope this helps. Best regards, Jim _______________________________________________ Flightgear-devel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
