Place things

Getting a thing to sit on another thing sounds like the easy part and is where most graphs first go wrong. Type in a height and it looks right, then you change a size and everything floats or sinks. The fix is to never type the number: let the graph measure it.

When you need this something has to rest on, join to or follow something else.

Put this on that

Place On takes the thing going on top and the thing underneath, and moves the first so it meets the second. It measures both every time it runs, so it stays correct when either one changes size.

Leave the underneath input empty and it seats the shape on the ground instead. That is the everyday use, because a shape is built around its own middle and so starts half buried.

Its Gap is signed. Positive floats a thing above, negative sinks it in, which is how a rock beds into soil rather than perching on it.

The one ordering rule: seat last. A Transform after a Place On sets its own position outright and quietly undoes the seating.

Why a typed height fails

A typed offset is right at exactly one size. It is exact when you author it, which is what makes it so convincing, and wrong at every other size you or a knob later choose.

This is the single most common reason a graph that looked finished falls apart when someone moves a slider.

Named points, for parts that swap

Place On is approximate on purpose: it stacks by measurement. When you want a designed joint, give both parts a named point and let them find each other.

Put a Socket on the handle where the head belongs, put a Socket with the same name on the head where it meets the handle, and Attach brings the two points together. Lengthen the handle and the head follows, because the point moved with it.

The real payoff is interchangeability. Any head carrying that name fits any handle carrying it, with no repositioning, which is what makes a family of parts rather than one model.

A socket carries no geometry and never counts toward a shape's size, so it can sit anywhere without affecting anything that measures the part.

Following uneven ground

On a flat surface, points are already at the right height. On anything bumpy they are not, and Drop To Surface pushes them down until they land.

That is what stops scattered rocks hovering over a hillside, and it works after the ground has been shaped rather than before.