> Really, we need a routine that works with an arbitrary ssg scene
> graph.  It's very concievable that someone could import scenery from
> some other project with a completely different layout.  Also, we are
> talking about non-vertical intesection lines when it comes to landing
> gear, so a line could intersect 'outside' the current tile there.  I
> was talking to someone else recently about a terrain collision warning
> tool and in this case, we'd be projecting a line forward so there is a
> high likelihood that the intersection point there would be outside the
> 'current' tile.

I agree.  Can we put vertical walls around each tile, that are transparent
for rendering but will be hit during intersection searches ?  For all 
non-airport tiles, there are only four walls so the impact is trivial.
Given that premise, we can do our intersection search efficiently for
a single tile.  Only if the search decides that the vertical wall is the
closest triangle do we panic and force a global search of all scenery.

The airline people are going to want GPWS and the helicopter people really
need radar altimeters.  Ground effect modelling by the FDMs also needs
accurate terrain heights on the perimeter of airports.  The only reason
why this looks like a gear problem is because the other features are absent.

_______________________________________________
Flightgear-devel mailing list
[EMAIL PROTECTED]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel

Reply via email to