SGDK isometric

Keep the map, movement surfaces and drawing separate. Isometric projection makes a 2-D world with height look three-dimensional; it does not supply physics, resource streaming or automatic depth sorting in SGDK.

Establish the coordinate contract

Choose tile width/height, map units, vertical scale, foot anchors and rounding. Use world coordinates for collision and surfaces, then project and subtract the camera for display. Keep the camera out of draw-order comparisons. Read coordinates and elevation for formulas, known-height inverse projection, stairs, underpasses and controller mapping.

A character's elevation is not its drawing depth. Sorting by screen Y or x + y - z alone fails when one character walks above a bridge and another walks beneath it. Use a simple foot-depth key only when the content's assumptions make it sufficient. Read depth and occlusion before choosing a sorter or splitting scenery.