Draw Order

[jbensman]

Does anyone understand how draw order works when there are multiple transparent maps showing?  I seperate topo and trails in different maps.  I use custom typ files which allow you to specify draw order.  That seems to work fine for that particular map, but when more than one map set is shown together, the order is not respected.  The specific issue is for my trail maps I include Corps of Engineers polygon shapefiles for dams and docks.  I set them at a higher drawing order than the river.  But the river draws on top of the dams and docks. 

[Boyd]

I think that polygon features on a transparent map will cover up everything on a map beneath... right?

[jbensman]

Yes, with one exception.

My problem is I have polygons in two different map sets.  I set one polygon (man made area)higher for the one map set than small river is set in the other map set.  So man made area should draw on top of the small river but the small river draws on top of the man made area. 

The exception is with a custom typ file you can make the pologon only draw everyother dot.  So you end up with a transparent polygon.  I use that trick in my land ownership maps.  On my topos I also use it on rivers so they do not cover up the roads across them (but there are problems with this that are a pain to deal with. 

[maps4gps]

I do not recall seeing a polygon (hydro or other) cover-up (display after) the lines, points, and/or labels in the SAME mapset.  Polygons in an overlay/'transparent' mapset will display after and cover-up the polygons, lines, points and labels in the 'base'/non-overlay/transparent mapset and also any custom 'raster' map image being displayed.  I do not have any Birdseye imagery nor recall testing this with tracks; however, lines in an overlay/transparent mapset will display after and cover tracks (I would expect points and labels would also).

I have experienced some inconsistent results when using more than one overlay/transparent mapset; this is when using custom type styles and sendmap to create small test 'files' and renaming each on the OR300.  They usually are combined in a single mapset box; perhaps the GPSr is getting confused about which custom type style to use.  I have not experieced this when installing the mapsets and using MapSource to 'send' (and rename) each seperately.

[Boyd]

I do not have any Birdseye imagery nor recall testing this with tracks; however, lines in an overlay/transparent mapset will display after and cover tracks (I would expect points and labels would also).

Point features, line features and tracks will be drawn on top of BirdsEye imagery. Polygons will not show at all when BirdsEye is enabled.

[jbensman]

Yes, the problem is two different transparent mapsets having polygons.  It sounds like no one knows how the GPS determines which polygon to draw first when there are more than one map with polygons.

Polygons in City Navigator do not show with Birdseye or Custom maps, but the poligons in transparent map sets draw on top of birdseye/custom maps.

[maps4gps]

I have not heard of Garmin giving information about how things are designed or work to anyone.
As Stan (cgpsmapper) pointed out; were are learning by trial and error.
I suspect we are currently trying to do things Garmin never envisioned they would ever have a need to do.