3D structural frames

Use a 3D Frame when the structure does not lie in one plane. A space frame, a corner portal with a roof beam, a cantilever that also bends out of plane.

The editor is the same family as 2D Frame: Node, Member, Load, Sections, Solve. The extra work is in space. Each node has x, y, and z. The solver is a linear-elastic space frame with six degrees of freedom per node (ux, uy, uz, rx, ry, rz).

Answers still become worksheet names. Math that reads them must sit below the region in evaluation order. Loads, section sizes, and Young's modulus must be defined above it.

Place the region

1. On the Insert tab, choose 3D Frame.
2. Click the page. You get the same chrome as 2D: tools on top, sketch in the middle, Details on the right. The camera starts front-on, looking at the XY plane, so the first sketch matches a 2D elevation.
3. Set Unit and Prefix before the first Solve. The default prefix is f3, so it will not collide with a 2D frame that still uses fr.

Orbit, pan, and zoom

Gesture	What it does
Left-drag empty space (Select tool)	Orbit around the frame. A click with no drag clears the selection; dragging keeps it. The axes triad in the sketch shows X red, Y green, Z blue. Y is up, matching the 2D elevation.
Alt-drag, right-drag, or middle-drag	Pan. Same as 2D.
Scroll or pinch	Zoom toward the pointer.
Iso, Top, Front, Side	View presets. Front is the 2D elevation: looking along −Z.
Fit	Frame the model in the view without changing the orbit angles.

View

Next to Selection and Sections is View. Turn node and member labels off when the sketch is crowded, or hide Loads so arrows do not cover the members. Perspective foreshortens the camera; the working plane and tools stay the same. Leave it off for a 2D-style elevation. Render, next to Grid on the status bar, draws each member as its section — I, tube, angle, and the rest — in steel grey. Open the Sections tab and those solids take the catalogue colour. Members without a complete section stay as lines.

Working plane

Nodes and loads are placed on one plane at a time: XY, XZ, or YZ. The status bar names the plane and the locked coordinate, for example XY at z = 0.

Select a node, then switch plane. The locked coordinate jumps to that node, so the next joint you place stays in the plane through the selection. Sketch a portal on XY, select a top node, switch to XZ, and draw the beam that leaves the plane.

You can still type x, y, and z in Details for an exact point. Dragging a node keeps it on the current plane through that node. Set as origin shifts the whole model so that node is (0, 0, 0). The red, green, and blue axes sit at that origin.

Pattern

⌘-click or Shift-click to add nodes and members to the selection. Details then shows Pattern: an axis, how many extra copies, and a spacing. Pattern copies the selection along global X, Y, or Z. If a copied node lands on a joint that is already there, that joint is reused and the new beam connects to it instead of stacking a second node.

What else is 3D

• Supports. Pin holds translations and torsion. Fixed holds all six. Roller holds Y and Z so a planar beam cannot fall sideways. X-roller and Z-roller restrain those axes only.
• Loads. Joint loads have Fx, Fy, Fz and Mx, My, Mz. Member point loads have Fx, Fy, Fz. A UDL can run in global X, Y, or Z, or in local y or z of the member.
• Pin releases. A pin end releases both bending planes (ry and rz), same idea as 2D, now in space.

Sections, diagrams, callouts, and the names Solve writes follow the 2D page, including the colour square on each section. Open the Sections tab and members take that colour; switch away and they return to the usual ink. Open 2D structural frames for the Node, Member, and Load tools, the Sections catalogue, and the full list of result names. In 3D you also get out-of-plane terms: uz, Rz, Mx, My.