Drawing and modifying

Terrafold models with edges and faces. Draw edges, and when they close a flat loop a face appears. Pull a face to make it 3D. Geometry that touches sticks together: edges split and join where they meet. To keep a part separate, make it a group or a component.

Every tool tells you what to do next in the status bar, and Window ▸ Default Tray ▸ Instructor explains it in more detail. Press Escape to cancel a tool's current operation.

Inference: snapping to points and directions

While you draw, Terrafold snaps the cursor to useful points and directions and shows a coloured marker with a tooltip.

Marker	Snaps to
Green circle	Endpoint, or the Center of a circle or arc
Cyan circle	Midpoint of an edge
Red square	On Edge
Blue diamond	On Face
Red, green or blue line	On Red Axis, On Green Axis, On Blue Axis
Magenta line	Parallel to Edge or Perpendicular to Edge
Grey	On Line (extending an edge), On Guide, Guide Point

To lock a direction:

Hold Shift to keep the current inference while you move the cursor elsewhere.
Press an arrow key: Right locks the red axis, Left the green axis, Up the blue axis. Down locks parallel, then perpendicular, to the last edge you hovered. Press the same arrow again to unlock.

Draw lines

Draw ▸ Lines ▸ Line (L). Click a start point, then click each next point. When the edges close a flat loop, a face appears. Type a length and press Enter to fix the length of the current segment.

By default, the Line tool accepts both clicks and drags, and keeps drawing from the end of each line. You can change both in Preferences ▸ Drawing.

Draw ▸ Lines ▸ Freehand sketches a curve: press, drag and release.

Draw rectangles

Draw ▸ Shapes ▸ Rectangle (R): click one corner, then the opposite corner. Type 3m,2m to set the size exactly. Hold Ctrl to draw from the centre.
Draw ▸ Shapes ▸ Rotated Rectangle: click two corners to set one side and its direction, then a third point for the other side.

A rectangle lies on the face under your first click, or on the ground.

Draw circles and polygons

Draw ▸ Shapes ▸ Circle (C): click the centre, then a point on the circle. Type a radius, or a number followed by s (such as 48s) to set the number of sides.
Draw ▸ Shapes ▸ Polygon: click the centre, then a corner. Type the radius or the number of sides (8s). Ctrl switches between a radius to the corners and a radius to the middle of the sides.

Draw arcs

Command	How it works
Draw ▸ Arcs ▸ Arc	click the centre, the start and the end
Draw ▸ Arcs ▸ 2 Point Arc (A)	click the two ends, then move out to set the bulge; type the bulge or a radius such as `50cm r`
Draw ▸ Arcs ▸ 3 Point Arc	click the start, a point on the arc, and the end
Draw ▸ Arcs ▸ Pie	click the centre, the start and the end; the slice becomes a face

Push and pull faces

Tools ▸ Push/Pull (P). Click a face, move to pull it out or push it in, and click again. Type a distance to set it exactly.

Double-click a face to repeat the last distance.
Hold Ctrl to keep the original face and start a new one.
Hold Alt to move the face and stretch the faces around it instead of creating new sides.
Push a face all the way through a solid to make a hole.

Move and copy

Tools ▸ Move (M). Click a point to move from, then a point to move to. Select first to move several things. When you move edges or vertices, connected faces follow and fold where needed.

Press Ctrl (Option on macOS) to make a copy.
After a copy, type 5x for five copies in a row, or /5 for five copies spread between the two points. You can type a new distance afterwards and the array keeps its count.
Hold Alt to fold faces that the move bends.

Rotate

Tools ▸ Rotate (Q). Click the centre of rotation, then a point that sets the starting direction, then the end direction. Type an angle to set it exactly.

Press Ctrl (Option on macOS) to rotate a copy. Afterwards type 6x for six copies around the centre.

Scale

Tools ▸ Scale (S). Select something, then drag one of the grips. Corner grips scale evenly; edge and face grips stretch along their axes.

Type a factor (2, 0.5), a factor per axis (2,3,0.5) or a length. A negative factor mirrors.
Hold Ctrl to scale about the centre, Shift to switch uniform scaling.

Offset

Tools ▸ Offset (F). Click a face (or select edges first), move in or out and click to draw a copy of the outline at a constant distance. Type the distance to set it exactly. Hold Alt to allow the offset to overlap itself.

Follow Me

Tools ▸ Follow Me sweeps a face along a path. Select the path edges first, then click the face to sweep. A circle as the path turns a profile into a revolved shape, such as a vase or a column.

Flip

Tools ▸ Flip mirrors the selection. Select what to mirror, then click the red, green or blue plane to flip it across.

Erase, hide and soften

Tools ▸ Eraser (E). Click or drag over edges to erase them; faces that depend on them go too.

Hold Shift to hide edges instead of erasing them.
Hold Ctrl to soften and smooth them, so curved surfaces look round.

Edit ▸ Hide hides the selection. Edit ▸ Unhide ▸ Selected, Last and All bring hidden things back. View ▸ Hidden Geometry shows hidden geometry dimmed so you can select it.

The Soften Edges panel (Window ▸ Default Tray ▸ Soften Edges) softens the selected edges by the angle between their faces, with Smooth normals and Soften coplanar options.

Edit ▸ Delete (Delete) removes the selection.

Intersect faces

Edit ▸ Intersect Faces ▸ With Model, With Selection or With Context adds edges where faces cross each other, so you can then erase the parts you don't need.

Paint with materials

Tools ▸ Paint Bucket (B). Pick a material in the Materials panel, then click faces to paint them.

Ctrl+click paints all connected faces.
Shift+click paints every face that has the same material.
Alt+click picks up the material of a face.

The Materials panel (Window ▸ Default Tray ▸ Materials) has:

In Model: the materials used in the model. Click one to start painting with it.
Library: the built-in materials, including colours, textures such as wood, brick, concrete and tiles, and physically based presets such as metals, glass, water and plastics. Click one to add it to the model.
Edit: change the name, colour, opacity, texture image and texture size of a material.

The garden tools add their own materials, such as Lawn, Gravel, Bark Mulch, Decking and Paving Slabs (see Hardscape).

Groups and components

Geometry inside a group or component does not stick to the rest of the model.

Edit ▸ Make Group wraps the selection in a group.
Edit ▸ Make Component (G) makes a component. All copies of a component share their contents: edit one and the others change too.
Double-click a group or component to edit its contents. Edit ▸ Close Group or Component (or a click outside it) closes it.
Edit ▸ Explode turns a group or component back into loose geometry.
When a group or component is selected, the Group ribbon tab offers Make Unique (separate one copy from the others), Reset Scale, Lock and the solid tools. Edit ▸ Lock and Edit ▸ Unlock protect groups and components from changes.
View ▸ Component Edit ▸ Hide Rest of Model and Hide Similar Components help you focus while you edit.

The Components panel (Window ▸ Default Tray ▸ Components) lists the components in the model with thumbnails and counts. Click one, or drag it into the viewport, to place a copy. On the desktop, the Local Library tab shows a folder of .tfo files (by default ~/Terrafold/Components) that you can place as components, and you can save a component to it.

The Outliner panel shows the tree of groups and components. Use it to select, rename, hide, lock, or drag a group into another group.

Measure and add guides

Tools ▸ Tape Measure (T): click two points to measure the distance. Starting on an edge draws a parallel guide line; Ctrl switches guide creation on or off. Type a new length after measuring to resize the whole model.
Tools ▸ Protractor: click the vertex of an angle, a point on its first leg, then the direction of the guide. Type an angle or a slope (1:2).
View ▸ Guides shows or hides guides. Edit ▸ Delete Guides removes them all.
Tools ▸ Axes moves the drawing axes: click a new origin, then the red direction, then the green direction.

Dimensions and text

Tools ▸ Dimensions: click two points (or an edge), then move away and click to place the dimension. Dimensions update when the geometry changes.
Tools ▸ Text: click an entity to attach a label with a leader, or click empty space for screen text. Double-click a text to edit it.
Tools ▸ 3D Text: type the text, pick a height and whether it is filled or extruded, then click to place it as geometry.

Solid tools

A solid is a group or component that encloses a volume: a closed surface with no holes and no stray edges. Entity Info shows Solid Group or Solid Component and its Volume.

Click the first solid, then the second:

Tool	Result
Tools ▸ Solid Tools ▸ Union	both solids joined into one
Tools ▸ Solid Tools ▸ Intersect	only the part where they overlap
Tools ▸ Solid Tools ▸ Subtract	the second solid minus the first; the first is used up
Tools ▸ Solid Tools ▸ Trim	the second solid minus the first; the first is kept
Tools ▸ Solid Tools ▸ Split	three pieces: each solid minus the other, and their overlap
Tools ▸ Outer Shell	everything merged, keeping only the outside surface

Results are new groups. Faces keep their materials, and soft edges stay soft. Over something that is not a solid, the tool shows Not a solid group or component and won't use it. Union keeps hollow spaces inside; Outer Shell removes them.

If two solids touch only along an edge, the result can't be one solid. Terrafold then keeps each piece as its own solid group and says so in the status bar.

Section planes

Tools ▸ Section Plane: click a face to place a section plane on it. The model is cut away in front of it. Use the arrow keys to choose the plane's orientation before you click.

View ▸ Section Planes shows or hides the planes, View ▸ Section Cuts turns the cut on or off, and View ▸ Section Fill fills the cut surfaces.
The Section ribbon tab offers Active Cut and Reverse for the selected plane.
File ▸ Export ▸ Section Slice… saves the cut outline as an SVG drawing.

Scenes

A scene saves a view of the model: the camera, hidden geometry, visible tags, active section planes, style, fog, shadows and axes.

View ▸ Animation ▸ Add Scene saves the current view as a scene. Update Scene and Delete Scene change or remove the selected one.
View ▸ Scene Tabs shows a tab for each scene above the viewport. Click a tab to go to that scene with a smooth camera transition.
The Scenes panel (Window ▸ Default Tray ▸ Scenes) lists, renames, reorders and describes scenes, and chooses which properties each one saves.
View ▸ Animation ▸ Play plays the scenes one after another. View ▸ Animation ▸ Settings sets the transition time and the delay at each scene.

To save the animation as images, see Rendering.

Terrain

The Sandbox tools under Draw ▸ Sandbox and Tools ▸ Sandbox build and shape terrain. They are described with the other landscape tools in Terrain and grading.