Frame Editor Reference

Positioning planes

A positioning plane fixes one world coordinate so a two-dimensional pointer click can produce one unambiguous point in three-dimensional space.

Definition#

A positioning plane is a temporary Frame Editor tool for placing or moving an Absolute node in the 3D scene.

A pointer position on the screen supplies only two dimensions. The plane supplies the missing constraint: it fixes one world coordinate while the click selects the other two.

The plane is an editing context, not a frame entity. After placement:

  • the Absolute node stores XYZ coordinate expressions;
  • it has no persistent dependency on the plane;
  • the plane contributes no geometry or manufacturing output;
  • leaving placement mode removes the highlighted plane from the scene.

Plane choices#

The plane name lists the two coordinates selected by the scene click. The omitted coordinate is fixed by Distance:

  • XY: the click chooses X and Y; Distance fixes Z. XY at 40 places points at Z = 40.
  • XZ: the click chooses X and Z; Distance fixes Y. XZ at 20 places points at Y = 20.
  • YZ: the click chooses Y and Z; Distance fixes X. YZ at -15 places points at X = -15.

This naming rule is more reliable than judging the highlighted plane from the current camera angle.

Plane distance#

Distance is the fixed coordinate measured from the world origin along the plane's positive normal:

  • XY distance is the Z coordinate;
  • XZ distance is the Y coordinate;
  • YZ distance is the X coordinate.

Positive and negative distances are both valid. XZ at 0 coincides with the default floor grid; XZ at 20 is parallel to it and 20 mm above it.

For a new Absolute node, placement starts on XZ at Y = 0. When moving an existing Absolute node, the initial XZ plane passes through that node at its current Y coordinate. If you switch plane while moving it, the editor places the newly selected plane through the node's current position so changing the tool does not immediately move the model.

Adding Absolute nodes#

Choose Absolute node from the frame-level Add menu. The editor enters placement mode, displays the plane controls, and highlights the active plane.

The usual workflow is:

  1. choose XY, XZ, or YZ;
  2. set the fixed-coordinate distance;
  3. inspect the highlighted plane in the scene;
  4. click one or more positions on it;
  5. choose Exit when placement is complete;
  6. select each node and verify or refine its exact coordinates.

Placement mode remains useful for creating several nodes on one shared plane. Every click creates a separate Absolute node using the current plane and snapping settings.

Moving an Absolute node#

Select an Absolute node and choose Move to reopen plane placement for that node. Choose the plane that exposes the two coordinates you intend to change, then click its new position.

For example, moving a node on XZ changes X and Z while the plane preserves Y. This is convenient when a point must remain at a known height.

The positioning plane does not permanently lock that coordinate. After leaving placement mode, direct edits to the node's XYZ expressions may move it away from the plane.

Relative nodes use a different operation, Position on link, because their authored constraint is a relationship to a Virtual link rather than a free world-space plane.

Grid snapping#

The Snap to Grid Node default controls scene-click rounding with Off, 1 mm, 5 mm, and 10 mm choices.

While an axis-aligned positioning plane is active, snapping rounds only the two coordinates chosen by the click:

  • XY snaps X and Y;
  • XZ snaps X and Z;
  • YZ snaps Y and Z.

The fixed coordinate still comes from Distance. Snapping is an input convenience, not a persistent constraint: later numeric or reactive-property edits are not forced back to that grid step.

Use a snapped click to establish a useful approximate or regular position, then inspect the node card. Its coordinate expressions and resolved values are authoritative.

History and dependencies#

Entering placement mode, changing the active plane, creating or moving a node, and leaving the mode are reversible editor transactions. Undo can therefore restore both model state and the contextual placement workflow.

Moving an existing node may propagate through links, Relative nodes, attachments, and reconciliation. The plane chooses the new Absolute position; the normal dependency engine owns everything that follows from that edit.

Common mistakes#

  • Choosing a plane by appearance alone. Orbiting can make any plane look slanted. Use the plane name and fixed-coordinate rule.
  • Reading Distance as camera depth. It is a world-axis coordinate, not distance from the camera.
  • Using XY to set height. In a Y-up frame, XZ fixes Y and therefore controls height above the floor.
  • Expecting the plane to remain attached to the node. It is a temporary placement tool, not a constraint entity.
  • Assuming snapping makes an exact design relationship. Use coordinate expressions or a Relative node when the relationship must survive later changes.
  • Moving a Relative node on a world plane. Edit its Virtual-link reference and axial or radial position instead.

Read Coordinate system and units for world axes, millimetres, and camera independence, or Nodes for choosing between Absolute and Relative positioning.

Watch the Triangle Frame narrated build to see the positioning plane introduced before the frame's first Absolute node is placed.