On Tue, Oct 16, 2012 at 2:54 PM, James Turner <zakal...@mac.com> wrote: > > On 16 Oct 2012, at 13:38, Tim Moore wrote: > >> The tile data on disk is actually stored in a >> coordinate system that is aligned with the earth-centric system, so Z >> points to the north pole. We rotate the coordinates back to a local >> coordinate system because that provides a much more useful bounding >> box for intersection testing and culling... and also lets you program >> snow lines in shaders :) > > Uh, are you sure about that? My understanding is that the BTG coords on the > disk are in 'tile local' coords, i.e 'Z is up' > > James https://gitorious.org/fg/simgear/blobs/next/simgear/scene/tgdb/obj.cxx#line925
I don't have access to a local copy of the tree at the mo', but I remember that this was introduced by Mathias when he added BVH. Tim ------------------------------------------------------------------------------ Don't let slow site performance ruin your business. Deploy New Relic APM Deploy New Relic app performance management and know exactly what is happening inside your Ruby, Python, PHP, Java, and .NET app Try New Relic at no cost today and get our sweet Data Nerd shirt too! http://p.sf.net/sfu/newrelic-dev2dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
