Best Method For IsoMetric Multi-Level Map Storage

I would make up each tile as a model with a specific name (supposing you're using 3D tiles), place them in Blender, replicating them by ALT+D, then export to collada.

If this is too complicated, here's a method I've used in the past with moderate success.
I used a spreadsheet which would export in CSV.
Each spreadsheet cell would contain one or more of the following codes

• nswe: an exit is present going north-south-west-east
  
• o: origin of layer. Different floors were assembled by matching origin position. Origin had position (0,0)
  
• other stuff you're likely not interested
  
• in your case, you might add a tag such as TILE:NUMBER to select model. Or maybe TILE:IMAGERESOURCE.
  
  This proven quite fast for defining layouts. As 3D information is not readily available, matching positions between different floors [size=2]("I want this room to be on top of... this other room below") proven more involved than predicted. I then switched to the blender+collada oriented method and I'm now very happy with it.

I should be a little more specific. Currently my "world" is stored internally as a Dictionary. The vector class is, as you may have gathered, a simple vector with x, y, z values. The Tile class holds data related to a specific title, as well as a Sprite class. I'm thinking the best bet is to divide the map into chunks, and serialize the resulting chunk class, dictionary and all. Comments?

I ended up just writing a file for a 10 (layer) isometric world that was 1000x1000 the filesize would get huge... mostly all of those tiles were blank.
So I ended up having my base tile and any layers of tiles above it would be part of a vector(data vector) (increasing with the Z axis) I could just check at draw time.

I ended up doing something like this as output binary to a file:

(int) FileVersion
(int) Checksum - The checksum is the total of the tilenumber for each given tile used to check data integrity.
(int) Number of tile records - I only store tiles that actually have data on them (On the base 0 level)

(for each base tile)
(int) X
(int) Y
(int) Tile - Add to checksum
(int) Number of Additional Levels on this tile
----(If > 0 parse each addtional level)
{
[indent=1](int) X
[indent=1](int) Y
[indent=1](int) Tile - Add to checksum
}

(As always I am sure there are way better ways of doing this)

Ah... If I serialize the dictionary, that will do for now, but ultimately I shouldn't be serializing the sprite as well, which I will be at first. Silly. =D

Ah... If I serialize the dictionary, that will do for now, but ultimately I shouldn't be serializing the sprite as well, which I will be at first. Silly. =D

What I was trying to say was just store the pertinant data to save and load and ignore everything else =)
(Which is exactly what you just said)

Dictionaries are neat I need to use them more often.
I think as a hold over from C++ I tend to store all of my stuff in vectors of a given class and refernce everything by a number.
Something like:
int TileReference = y + (MapWidth * x) ;
Then you could have s single 1d vector with all of your map tiles (as part of a class) in it making it really easy to export / import data.