On Wed, Nov 15, 2006 at 01:09:49PM -0500, Frank Warmerdam wrote: > Trond Michelsen wrote: >> I'm having some problems getting mapserver 4.4.1 to draw maps in an >> oblique projection. > First, there has been a variety of work on the "world mapping" problem > since 4.4.x. I would encourage you to try again with 4.10.0 and see > which problems remain.
Ah, OK. Thank you. We have installed mapserver from a .deb package for Debain Sarge, and I don't think there's a newer version available. If possible, I'd like to avoid building from source, but it seems that this is the only alternative in this case, so I'll give it a shot. > The core problem relates to computation of a spatial filter to use against > the lat/long data to select all the features needed for rendering. Originally > I believe the corners of the bounding box in the output coordinate system > were reprojected back to the source coordinate system and used to form a new > bounding box. This works very poorly in world mapping situations such as > yours where the pole (an extreme in lat/long) is in the middle of the > projected space. > > Recent versions of MapServer will "sample" through the destination rectangle > to collect an MBR in the source coordinate system if it detects that some > edge points are not reprojectable. I'm not sure if this will fix your > problem or not. There have been some other changes for world mapping that > might also prove useful in your case. Thanks. I'll give it a try, and let you know how it turns out. > If you still have problems in 4.10.x then please register a bug with a > reproducable situation and we can contemplate what to do about it. Sure. -- Trond Michelsen
