Maximillian I got a little bit interested in your inquiry as shown in the attached therion dataset. The pdf files show the results of changing various parameters. This is a bit rambling and perhaps lacks direction, but maybe it is of use to someone. The transparency or otherwise of particular entities depends on; -mainly the symbol definition (does it have an opaque background written into the definition?), -then the transparency and opacity settings used in the layout, -placement (top, bottom) and order in which it is drawn in the individual scraps, -and probably some other things I haven't thought of. The first symbols drawn tend to be placed at the bottom. As you draw each symbol tends to overlie the ones previously drawn. If you look at the th2 file with a text editor you will see that as you draw, each item is entered before the previous item; so as with map definitions, the first entities in the file are on top of the ones further down. If you check in the therion book "How the map is put together" you will see that it is really more complicated than this and that therion anticipates that some types of entities are usually above other types regardless of their placement in the file. You can modify this a little by using -place top or -place bottom on a case by case basis. In practice I find that if you are fussy, fine adjustment takes a lot of experimentation. Still, in general I think it is a good idea to draw things at the bottom first (the sump area fill) and things near the top last (the water fill - which is how an airbell will look). I have experimented with two ways of drawing area water over area sump (near stations B6 & B7). The area associated with border id l26-543-625 made me think that enabling line border to have -outline [out in none] (similar to walls) would make definitions of areas (associated those borders) with holes in them easier to draw. Low priority as there is a workable but slightly more complicated alternative for the draughtsperson as in the attached. I always use purpose drawn line border as a boundary for fills, as this minimises problems with areas becoming disassociated from there borders if lines are split in two during subsequent edits. border # I tend to use this to define area water border:invisible # I tend to use this to define area sump Which brings me to a question. Why are some borders to water areas in my example thick & some thin? The borders near B5, B6, B7 & B8 should all be the same, but B6 is thinner? This sort of thing in the past has been due to bugs in the symbol definitions in metapost. Only thing is that it is happening with both the default symbols and with my custom symbols, so to me that points to a problem with my drawing of the scraps - cannot find it though! Regards Bruce
I'm trying to draw cave passage which are mainly flooded but have a few places where you can surface due to air filed domes. See http://static.23.nu/md/Pictures/ZZ6E08C628.png - the orange parts are the ones where we can breathe air.
How do I draw something like this? Two layers, or an area where we can surface? If so which kind of area is preferred?
Regards Maximillian Dornseif