Map Priorities and Layering.

[losted]

Hi all, great site!
Have been lurking for a while and scanning Indexes but could not find anything about Garmin Map priorities and Map overlay conventions.
If anybody could point me to some references it would be appreciated.
Tks.

[Kanopus]

Garmin can display multiple map at once. What you will see, which map will be on top, depends on 2 main factors:
- type of the map
- internal map priority and transparency settings

There is a list indicating priority according to map typ, from the top to bottom:
City Navigator
City Select
MetroGuide
BlueChart
Fishing Hotspots
Water Waypoints and Lights
Road & Recreation
Topo
WorldMap

I'm not sure how precise is this list, but i can confirm, that type of the map is important.

Second factor is draw priority. It is a number in range 0-31 hidden inside img. This value can be edited by some tools. Map with bigger priority are displayed over other maps.

Map can have transparency attribute. It makes map polygons invisible. Transparent maps are displayed over non-transparent maps.

Both factors are used by GPS when drawing maps, but i really don't know, how exactly draw order is calculated. Draw priority is a simple number, changing it gives expect effect, but it is difficult to tell, how map type is converted or compared to priority numbers.

[losted]

Thanks Kanopus. I'll see what I can do with that info.

Losted

[DTPM]

On my SD card I have four maps of the same country merged with Gmaptool.

If I have all maps 'turned on' in my 'settings, map, map info' will my garmin just select the most appropiate map for the road im on or does it prioritise the garmin maps first?

The reason I ask is I am going to a remote part of India, CN only has main roads, MapMyIndia seems to have more, India Satguide maps had some different streets and a Himalaya map has a chunk of my journey. Am I better off leaving everything turned on and let the machine (Zumo 660) figure it out, or, do I keep checking maps as I go to see which is suitable?

[DTPM]

Had a good read.

Apart from CN taking priority, Im none the wiser

[grv2k5]

The one in the SD card would always take priority

[catymag]

The one in the SD card would always take priority

I would like to know where you got this info-

[DTPM]

The one in the SD card would always take priority

All of the maps are on a SD card.

Apart from CN taking priority I dont think anyone can give me an answer as map priority depends on a hidden number in the maps.

[catymag]

It depends also on the device. In my 62 for example ,map drawing priority is completely different than in nuvis.
Must manage maps showing ,using profiles coz some topos always hide other maps ,even CN.

This thread merged with the previous one.

[leitz5138]

On my SD card I have four maps of the same country merged with Gmaptool.

If I have all maps 'turned on' in my 'settings, map, map info' will my garmin just select the most appropiate map for the road im on or does it prioritise the garmin maps first?

The reason I ask is I am going to a remote part of India, CN only has main roads, MapMyIndia seems to have more, India Satguide maps had some different streets and a Himalaya map has a chunk of my journey. Am I better off leaving everything turned on and let the machine (Zumo 660) figure it out, or, do I keep checking maps as I go to see which is suitable?

I've tried to enable at the same time 2 maps of the same country: the first coming from Mapsource and the 2nd one is made by a third party. This way It seems not to work very well on my Nuvy205.