Nodes

Definition#

A node is a named logical point in a frame. Nodes locate links, attachments, and junctions, but a node is not itself a tube, printable joint, attachment, or visible manufacturing feature.

Every node resolves to one position in the frame coordinate system. What distinguishes the two node types is where that position comes from:

• An Absolute node owns its X, Y, and Z coordinates directly.
• A Relative node derives its position from a Virtual link and moves when that reference changes.

Use a node whenever several relationships need to agree on the same point. Connecting entities to a shared node preserves that design intent when the frame changes.

Absolute nodes#

An Absolute node is positioned directly in world coordinates. Its X, Y, and Z values are authoritative and may be literal millimetre values or expressions driven by Frame reactive properties.

Choose an Absolute node for a point that establishes the frame rather than following existing geometry: an origin, a fixed mounting location, a base corner, or a principal apex. Moving it changes the geometry that depends on it.

The scene placement workflow uses a positioning plane because a screen click supplies only two dimensions. The selected XY, XZ, or YZ plane fixes the third coordinate. Snapping and clicking are convenient inputs; the numeric coordinate fields remain the source of truth.

Relative nodes#

A Relative node is attached to a Virtual link. Its position is described in that link's local frame instead of by independent world coordinates.

The axial position has three decisions:

• the reference terminal: the Virtual link's start or end node;
• the distance type: a relative ratio of the link length or an absolute distance in millimetres;
• the distance value or expression.

By default, the node lies directly on the Virtual link. An optional radial position moves it away from the link by a distance and angle while preserving the link as its reference.

Choose a Relative node for derived geometry: a midpoint, a repeated division, an offset mounting point, or any location that should follow a span. A ratio such as 0.5 preserves the midpoint when the link changes length; an absolute distance such as 40 mm preserves the distance from the chosen terminal instead.

Dependencies and propagation#

Nodes are part of the Frame Editor's dependency graph. When an Absolute node moves, connected Virtual links and Physical links are recomputed. Relative nodes hosted by those Virtual links then resolve their positions again, and dependent members and attachments follow through the same transaction.

This is why choosing the correct node type matters. An Absolute node says “this coordinate is independently important.” A Relative node says “this relationship to that Virtual link is independently important.” Both may occupy the same world position at one moment, but they respond differently to later edits.

A node can also own the reconciliation mode and ordered reconciliation specification for Physical links meeting at that logical junction. The explicit Reconciliation action changes ordinary manufactured-member terminals and Relative-node offsets around the node; it does not move the logical node itself or create a special junction entity.

Creating and editing nodes#

Create an Absolute node from the frame-level Add menu. Choose a positioning plane, place the point in the scene, then verify its exact coordinates in the selected node card. Use Move to return an existing Absolute node to the same positioning workflow.

Create a Relative node after at least one visible Virtual link exists. Select the reference link in the scene, then use the node card to choose its reference terminal, axial distance type and value, and optional radial offset. Use Position on link when the node should move to a different Virtual link.

Renaming, coordinate edits, relative-position edits, visibility changes, and dependent propagation are recorded as reversible transactions.

Properties and relationships#

The main user-facing node properties are:

• Name: the stable human-readable identity used throughout the editor and narration.
• Visibility: whether the logical point is shown in the scene; hiding it does not delete it.
• Position: Absolute XYZ expressions, or a Relative link reference with axial and radial positioning.
• Connected links: Virtual and Physical links that use the node as an endpoint.
• Hosted attachments: link attachments anchored at the node on their parent links.
• Reconciliation: the automatic or manual calculation recipe used when you explicitly reconcile Physical links meeting at the node.

The editor does not allow two distinct nodes to resolve to the same position. Reuse the existing node when several entities should meet at one logical point.

Manufacturing and export#

A node contributes no printable body or stock item by itself. It remains important to manufacturing because it locates member centre-lines, attachment anchors, and reconciliation intent.

Moving a node can therefore change exported Physical-link lengths and printable joint geometry downstream. Hiding a node changes only the scene presentation; deleting it can remove or reconfigure the entities that depend on it.

Common mistakes#

• Treating a node as manufactured geometry. A node has no radius, material, wall thickness, or printable body. Add a Physical link or attachment when the design needs matter.
• Using an Absolute node for a derived point. A manually entered midpoint will stop being the midpoint when its endpoints move. Use a Relative node with a 0.5 ratio.
• Using a Relative node for an independently fixed location. If a mounting coordinate must remain fixed while nearby geometry changes, use an Absolute node.
• Correcting the camera instead of the coordinates. View orientation does not change the model. Verify the positioning plane and numeric fields.
• Creating a second node at an existing junction. Shared geometry should normally share one node so dependencies and reconciliation remain coordinated.

Related learning#

Watch the Triangle Frame narrated build to see Absolute nodes establish the logical corners and ordinary Relative nodes locate reconciled member terminals.

Read Coordinate system and units for world-space conventions, Positioning planes for scene placement, Virtual links for the oriented references that host Relative nodes, Physical links for the manufactured members that use nodes as terminals, or Reconciliation for eligible logical junctions and endpoint adjustment. Return to the Frame Editor Reference index to browse every topic, or use the Getting Started vocabulary for a shorter overview.