Definition

A probe samples points across the usable bed. Between those points, firmware estimates the surface with an interpolation method and adjusts commanded Z as XY changes. The aim is consistent nozzle distance across the first layer, not to make a warped bed physically flat.

A mesh cannot repair loose mechanics, axis twist, probe bias or a bad Z offset. Results also depend on bed temperature, mounting and which profile is loaded. Adaptive meshes may cover only the current print area and are expected to be regenerated rather than blindly reused.

What matters in practice

Compensation, not repair

Software follows measured surface error; it does not straighten the frame or bed.

Interpolation between samples

More points are not automatically better if the probe is noisy or mechanics are unstable.

Active state matters

A stored profile helps only when the intended mesh is loaded and enabled.

Example in G-code

Two firmware workflows

; Marlin, mode-dependent
G28
G29

; Klipper
G28
BED_MESH_CALIBRATE

Both aim to measure compensation, but their commands and profile behavior are not interchangeable.

What this viewer can show

In this viewer

The viewer has no access to the printer's saved probe grid, current profile or live compensation. It shows nominal slicer coordinates and labels G29 or mesh macros without pretending to apply them.

Primary sources

This explanation uses firmware documentation and details visible in G-code. Your printer's settings still determine what the machine does.