Coordinate Systems (CS)

• GCS, the global coordinate system. There is one per setup, at (0, 0, 0). It cannot be moved, rotated, renamed or deleted. The breadboard lies at y = 0, and a new part is placed 10 mm above it at the point you clicked.
• LCS, the local coordinate system of a part. It defines the part's position and orientation, measured against the GCS by default or against another part's coordinate system if you link one.

A part can carry extra named coordinate systems, for example one aligned to a surface or an edge. One of them is the working LCS at any time; the others can be promoted later.

The GCS, every LCS and every extra coordinate system appears as a node in the PARTS tree. You can show, hide, rename and zoom to each one. When a part's Move & Rotate panel is open, the viewport draws a dashed line from the part to its reference coordinate system.

Select a part to see its Move & Rotate panel:

• Lock move & rotate: when checked, the fields are disabled and edits show a warning.
• Position X, Y, Z, in mm or inches.
• Rotation X, Y, Z, in degrees or mrad.
• Reset, which returns the part to its original transform.

Position and rotation are always relative to the part's reference coordinate system: the GCS, or the coordinate system you linked. Values update as you drag the part in the viewport.

To make one part's position follow another's, for example a detector that should stay behind a lens:

1. Select the part.
2. In Move & Rotate, click Press to pick reference CS.
3. Click the part or coordinate system to reference in the viewport. Click the button again to cancel.

A reference card then names the reference coordinate system, and the position and rotation fields read relative to it. Click the X on the card to remove the link.

Some parts cannot take a reference: members of a group, locked parts, and coordinate systems anchored to a chief ray.

Add → Coordinate System in the right-click canvas menu places a standalone coordinate system where you clicked. Move, rotate, rename or link it like any other part.

To align a coordinate system with a feature of an existing part, select the part and use the Add CS tool. It has two steps:

1. Select Point, the origin. Pick an Edge/Axis or a Surface in the viewport, or type the coordinates. Optomechanics and CAD parts default to edge picking, optics to surface picking.
2. Select Axes, the orientation, by one of: Direction by face, Direction by edge, Direction by points (two picked points), Direction by reference CS (copy another coordinate system) or Direction by values (type two axis vectors; the tool makes them orthogonal and derives the third).

Each axis can be flipped. Give the coordinate system a name and click OK.

Right-click a coordinate system in the tree:

The GCS cannot be moved, referenced, duplicated or replaced.

A chief ray coordinate system follows the chief ray of a light source and moves itself after every run. Use it for a detector or a fold mirror that should stay on the beam wherever upstream parts send it.

• Re-anchor on chief ray attaches it to the ray again after a change; a warning appears if the source no longer exists.
• Detach from chief ray turns it into an ordinary fixed coordinate system.

A chief ray coordinate system cannot be linked to a reference.

Availability: chief ray coordinate systems are not enabled on every account. If the options are missing, contact support.