Looking for information about pathfinding on isometric maps

I am working on a game engine called Engine1 (logo is a big steam train). I've been very successful with motion animation, sprite animation and element manipulation. I can create/destory/animate elements very quickly (about ~1000 elements every 1/40 of a second).

I'm now looking to expand my engine to include a library for isometric maps with path finding support. Please don't give me copy and paste code. I'm looking for information and theory about efficient algorithms for isometric path-finding.

I also plan on releasing my engine as open source after I release my own game with it first (proof of concept). If your interested in snagging an early build message me.

Solution

The basic grid path-finding algorithm is very simple:

Take your starting cell, recursively hit every adjacent possible cell
- ignore invalid cells, e.g. walls/etc
whenever you hit a cell, only continue if you're at the lowest step for that cell. e.g.:
Die whenever you're further than the best distance so far
```
A B C
D E F
G H I
```

You have several paths from A-I (in random order):

A-B(1)-C(2)-F(3)-E(4)-H(5)-I(6)
A-D(1)-E(2)-B(3) -- die because B(3) > B(1)
A-D(1)-E(2)-F(3)-I(4)
A-B(1)-E(2)-D(3) -- die because D(3) > D(1)