Hi Y'all, One of the things that's come up in the apt.dat discussions is whether the taxiway layouts should be "pre-clipped" (meaning there are no overlapping polygons) or "overlapped" (meaning polygons can overlap and there is a well-defined draw order that makes one appear on top of another).
(I think we have to pick one - having overlapping polygons with random draw order doesn't help authors make layouts.) I'm looking for pros and cons of each technique...here's some thoughts I've had: - I'm not sure about FG's scenery distro model, but pre-clipped polygons means that more work has been done to a layout before it becomes an apt.dat file, which would make on-the-fly loading of add-on scenery faster. - Any app will have to do clipping or draw order control - clipping can happen before or during app run. So a clipping model gives us a chance to keep work out of sim-run-time, but an overlapped model allows us to do work in the sim (e.g. avoid the need for preprocessing). I think FG is pretty strongly in the preprocessing camp right now. - Pre-clipping puts more burdon on content creation tools (by requiring them to have robust clipping to save the data) whereas not requiring pre-clipping puts more work on data consumers. - Personally I like pre-clipping because I've always found overlapping runway data to be..."messy". I always wonder if there isn't some polygon buried under another one, totally invisible to the user. So I tend to think pre-clipping makes a better editing environment. But this last point is probably not appropos to the discussion. Thoughts? Ben _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
