On Saturday 14 February 2004 13:43, Vivian Meazza wrote: > Lee Elliott wrote > > > On Friday 13 February 2004 22:27, Jon S Berndt wrote: > > > Any chance of modeling wingtip vortices (when CL is high > > > > enough above > > > > > some threshhold) and rocket engine exhaust? > > > > > > :-) > > > > > > Jon > > > > I've thought about trying this but I think it could only be > > really effective > > in level flight. As soon as you start banking the 'end' of > > whatever trail > > you're simulating will rotate (echos of the VRP issues:). > > > > For a very short trail this might not be noticable but for > > longer ones I think > > it's a bit of a show stopper. > > > > It would be possible to include curved trails in the model, > > and the select > > anim function could be used to select the appropriate model > > object, but then > > you'd need a wide range of trail objects. > > > > At first glance, this doesn't seem too bad, but then I think > > you'd really need > > several versions of each trail type so that you could switch > > between them to > > give the impression that the trail is changing throught time. > > > > Hmm... I don't think I've explained that bit very well... > > > > Consider an a/c in stable level flight where votices are > > being generated from > > the wing-tips. Even though the vortex trail may not change > > in length or > > shape, it's appreance will change from frame to frame, so > > you'd need to > > switch between several identically shaped and sized objects > > that are textured > > slightly differently to give the impression of change. > > > > If we could actually modify the model objects themselves then > > we could 'bend' > > the trails, and cut down on the number needed. > > > > But then we could also do wing flexing too. > > > > Before anyone starts thinking seriously about this, it would be very > > non-trivial to do, at least for the wings, where some objects > > would need to > > be 'bent' i.e. the wings and control surfaces, whereas other > > objects would > > have to simply translate i.e. wing mounted engine nacelles and U/C. > > > > For a simple object, like a vortex trail, bending might be > > feasible, and > > combined with scaling (which I think we already have), it > > might work ok. > > > > Another possiblity would be some sort of particle object > > handling where > > temporary objects could be generated, left for a while and > > then culled. We > > could then 'drop' a stream of these objects behind the a/c > > that're culled > > after a certain time. It'd probably need a lot of objects to > > work though, > > and it would also push up the object count of course. > > > > Both methods would need some carefull texturing. > > The second method could be very useful - drop tanks, ordinance, cockpit > canopies, ejector seats, tyre smoke on landing. Not a high priority, I > feel, but a nice to have. I want to do drop tanks on the hunter some time > soon, but I can probably handle them well enough with the existing > animations
I think drop tanks would be feasible but it would need some thinking about:) The fun bit will be counteracting the a/c manuevours after the tank has dropped so it falls straight even though the a/c may be climbing and banking. LeeE _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
