So let me get this right

[Geo]

@mallard

I’ve two cubes, and want to align the center of the two along an axis (think of a tower of cubes, centered on top of each other, each one smaller than the last).

I believe the fastest way is as @TIG described …To align objects use inferencing…
Infer and then click the Move tool on the bottom edge midpoint of a cube.
Then take that known point to another known point … the top edge midpoint of another cube.
That aligns their centers along one axis.
A second move, inferring to midpoints and constrained to the other axis, aligns their centers.

See: Inference Types — SketchUp Help … and then read Gully’s more eloquent description below.

Object Snap Tracking - does this feature exist in SketchUp?

Inferencing in SU is a system of dynamic guidelines and object snaps. As Thom Thom said, you can’t turn it off–it’s like gravity in that regard–but some forms of inferencing are rather bashful, so that not only do you not trip over them all the time, they need to be “encouraged” to make an appearance at all, generally by hovering. One of these is called From Point inferencing, whereby you can extend a dynamic guideline from a point along an axis if you hover over the point first (or as I like to…

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