Coordinate systems
Workspace, job, absolute, screen. Which one each control uses, and how they convert.
Beam Bench juggles four coordinate systems. Knowing which one you are looking at saves a lot of confusion.
The four systems
1. Workspace (machine) coordinates
Real-world millimeters on the machine bed. (0, 0) is the workspace origin, set by homing. Most diode and gantry machines put it at the bottom-left of the bed; some CO2 put it at the top-left. The Device Settings → Machine → Origin field tells Beam Bench which.
Used by: the machine itself (GRBL coordinates), the Move panel position display, jogging.
2. Job coordinates
Coordinates relative to the job's anchor, controlled by Start From and Job Origin in Laser Control.
If Start From is Absolute Coords, job = workspace. If Start From is Current Position or User Origin, job coordinates are offset by the head position or user origin so that the design's anchor lands at the chosen reference point.
Used by: the G-code planner.
3. Canvas (project) coordinates
What you see on the canvas in mm. (0, 0) is the bottom-left or top-left of the project's bed area depending on the machine profile's origin.
Used by: every UI control that shows position, Shape Properties, Properties Toolbar, rulers.
4. Screen (viewport) coordinates
Pixels in the canvas widget. Maps from canvas coordinates via pan and zoom.
Used by: mouse events, hit-testing, internal rendering. You rarely see these directly.
The conversions
screen ←→ canvas: pan, zoom (via viewport transform)
canvas ←→ workspace: identity (same coords, same units, sometimes flipped Y for top-left-origin machines)
canvas ←→ job: depends on Start From + Job Origin (see Laser Control)
job ←→ workspace: depends on Start From (User Origin offset, Current Position offset, or identity)Common confusions
"The cut landed in the wrong place"
The design was at canvas (50, 50) but the cut happened somewhere else. Almost always Start From / Job Origin mismatch. See Job origin vs workspace origin.
"The Y axis is upside down"
Different machines use bottom-left or top-left workspace origin. Beam Bench respects whichever the machine profile says. If the project was made for a different machine and you opened it on a top-left-origin one, the job appears mirrored. Fix in the machine profile.
"Inches vs mm"
The Display Unit only changes display. Beam Bench's internal coordinates are always mm. Switching units does not change the underlying data.
Why these are separate
The separation lets you place a design anywhere on the canvas relative to your machine without having to nudge it into machine coordinates first. You design at canvas (0,0), the bottom-left of the project, and Job Origin moves it to wherever you want it to actually run.