Assembly Snapping — Connecting Structural Components

Drag a component — for example a beam — toward a post. When the beam's beam-end socket comes within snap range of the post's post-top socket, the snap engine detects the compatible pair and highlights both sockets with a pulsing glow. The HUD label appears above the target socket showing its role (for example, POST TOP). An animated dashed line bridges source and target to show the pending connection. Release the component to lock the joint.

The snap HUD is a floating label that appears next to the target socket when snap is active. It shows the socket role in capitals (POST TOP, BEAM END, RAFTER END, RAIL TOP, GROUND). If two sockets are close but incompatible — a beam-end near another beam-end — the HUD does not appear and no connection forms. Use the HUD as confirmation that the right joint is engaged before releasing.

Auto-length is active by default for beam components. When you snap a beam between two anchor sockets — for example two post tops on opposite sides of a bay — the beam measures the socket-to-socket distance and sets its length to exactly that span. The bay width can vary freely; the beam adjusts each time. Toggle auto-length off in the Assembly HUD if you want to set beam length manually.

Fill patterns place repeated elements across a structural bay automatically. Select two anchor beams (or rails) that define the bay, then choose a fill pattern from the Assembly HUD: Rafter Fill spaces rafters at a set on-centre distance across the span; Decking Fill distributes boards across a frame gap; Fence Picket Fill spaces pickets evenly along a rail. Ghost geometry previews the filled result before you confirm. Standard on-centre spacings (400 mm, 600 mm in metric; 16 in, 24 in in imperial) are offered as quick-select options, or enter a custom spacing.

Post layout tools place multiple posts at once. Post Line: click two points on the canvas to define a run; set the post spacing and count, and a line of posts places along that path. Post Rectangle: click two corner points and posts fill a rectangular array at the chosen bay size. Standard spacings — 2.0 m, 2.4 m, 3.0 m (or 6 ft, 8 ft) — are available as quick options.

When you move a component that has locked socket connections, attached components follow it. Moving a post repositions any beams snapped to its top; moving a beam repositions any rafters connected to its face. This keeps the structural assembly intact as you adjust the overall layout without having to disconnect and reconnect each joint individually.

Once components are joined via snapped sockets, the connection graph treats them as a hierarchy. Selecting and moving a parent — for example a post — repositions every beam snapped to its top, and every rafter snapped to those beams. You can adjust the overall footprint of a pergola or deck frame by moving just the corner posts without disconnecting any joints. To break every joint on the selected piece, click Detach All in the Assembly panel — the piece becomes a free-floating component again.