Michael, What you are observing isn't exactly how you describe, although it appears that way. I was trying to simplify things by just pointing out that the aircraft stays horizontal (appears to not roll) in the chase view, but that isn't exactly how it works.
The difference is that the xyz offsets to the eye position are applied in relation to a vector that is perpendicular to the aircraft in the cockpit view and perpendicular to the ground, that is in relation to the earth (radial from center of earth or "world up") in the chase view. Since in both cases the same rotations are applied to the model, then you are seeing the effect of the difference in how the eye is positioned. The axis going to the right, is always in relation to the model (the aircraft orientation). The effect of this is as follows: In the case where the camera is offset in relation to world up (as in chase view) then the horizon doesn't move to pitch looking forward and doesn't move to roll looking sideways. Draw a picture for yourself and you can see what I'm talking about. In the case of chase view make the up axis that the eye is on parallel to a line that goes through the aircraft and is always perpendicular to the ground. However, let the eye rotate right and left with the model. This is not roll I'm talking about only rotation of the axis that the eye is on (can be due to pitch or roll or both). Anyway, this is why I suggested that you set the offset way back in the 3d cockpit view so that you were "following the aircraft" in cockpit view. When I get done with the first pass on the configurable viewer, experiment with that as well. Then we can go from there. Best, Jim That's why I suggested setting your z-offset way back behind the aircraft. Best, Jim Michael Selig <[EMAIL PROTECTED]> said: > At 4/2/02, you wrote: > >Michael Selig <[EMAIL PROTECTED]> said: > > > > > Chase views: > > > > > > [1] One view like the old one, but minus the sway that was due to > > > sideslip. In this case the horizon on the screen is always level. (I > > > don't think the new chase view behaves like this. The horizon is not > > > level, it rolls w/ the aircraft.) > > > > > > >Actually only the pitch is applied to the model. The roll is not. From the > >side it does look a little funky. In relation to the horizon, the pitch angle > >gets doubled. > > Maybe I should wait until you have it done, but I'd like to comment on my > observations which you are surely aware of. > > As things are now, one gets this when the model is viewed from behind: > - pitch is applied to the model > (model pitches up-down / horizon is level on screen) > - roll is applied to the view > (horizon rolls / wings are level on screen) > - yaw is applied to the view > (horizon swings side-to-side / model is straight nose-to-tail on screen) > > Then when the model is viewed from the side: > - pitch is applied to the view > (horizon rolls / aircraft is level --- opposite above) > - roll is applied to the model > (opposite above) > - yaw is applied to the view > (horizon swings side-to-side --- same as above) > > Things are halfway between these two with the quartering views. > > For me, speaking from experience, this is a recipe for vertigo. But I > guess it is also a cure for my addiction to flying the sim! > > Because I am not ready to be cured, I'd like to propose in these terms > above one basic view mode, which is somewhat similar to the way things > were. It goes like this: > > In rearview: > - pitch is applied to the model > - roll is applied to the model > - yaw is applied to the model > > In sideview, etc: > - same as above > > I think this would be a very intuitive view. In this case, the horizon is > always level on the screen and only the model rolls, pitches and yaws. The > viewer is always looking at the airplane from a point on a circular > perimeter that surrounds the airplane and this disk is always parallel to > flat ground. > > Regards, > Michael > > > > [2] What would be seen from a following aircraft. In this case, the > > > horizon will move like it does on the HSI. The final view will look very > > > much like the current cockpit view minus the instruments but w/ the 3D > > > model of the aircraft shown. > > > > > > >Hmmm...try setting the z-offset to -25.0 in the pilot view. > > > > > [3] A lagged version of [2]. Not as important, but neat. It would > > > effectively show what one would record from a video camera in the chase > > > plane. The 3D model of the aircraft will not always be centered on the > > > screen. In extremely rapid maneuvers, the 3D model might even move off of > > > the screen (out of the camera field of view). > > > > > > It seems that to do 2 and 3, the aircraft trajectory history (so many feet > > > of flight path trajectory) needs to be saved and used by the viewer code. > > > >Yes, some sort of fifo buffer would work. > > > > > Tower view: > > > > > > [1] One version w/ the view positioned at the end of the runway and > > > slightly behind and above the aircraft, looking down on the > > aircraft. This > > > view is extremely useful for testing new-aircraft nonlinear-aero > > > models. It's hard to judge stall and other extreme maneuvers from the > > > cockpit, but from the tower one can gauge these things pretty well. > > > > > > [2] Another from the tower at the particular airport. > > > > > > Maybe the latest code can already do these things w/ input via xml(?). > > > > > > >Almost. It should by the end of the week, maybe sooner. Once I have the > >basic viewer xml configuration setup, I will probably be expanding it to allow > >quite a lot of control via xml configs. > > > >Best, > > > >Jim > > > >_______________________________________________ > >Flightgear-devel mailing list > >[EMAIL PROTECTED] > >http://mail.flightgear.org/mailman/listinfo/flightgear-devel > > > > ************************************************** > Prof. Michael S. Selig > Dept. of Aero/Astro Engineering > University of Illinois at Urbana-Champaign > 306 Talbot Laboratory > 104 South Wright Street > Urbana, IL 61801-2935 > (217) 244-5757 (o), (509) 691-1373 (fax) > mailto:[EMAIL PROTECTED] > http://www.uiuc.edu/ph/www/m-selig > http://www.uiuc.edu/ph/www/m-selig/faq.html (FAQ) > ************************************************** > > > _______________________________________________ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > -- Jim Wilson - IT Manager Kelco Industries PO Box 160 58 Main Street Milbridge, ME 04658 207-546-7989 - FAX 207-546-2791 http://www.kelcomaine.com _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
