Creating a Cave

1. Place an entrance

1. On the Build tab, choose the Entrance style and click Place Entrance.
2. Click the floor point where the cave mouth should stand. A ghost shows the entrance.
3. Move the mouse to aim the green ghost tunnel (with arrows on its floor): that is where the passage goes into the ground. The blue Outside arrow marks the cave mouth. Click again.
4. Drawing of the first passage starts right away from the entrance.

Tip: on a terrain, place the entrance at the foot of a hill or cliff, then use Cut Terrain Opening (see Terrain).

2. Draw a passage

1. Click floor points one after another. A dotted line from the last point follows the mouse with the slope and distance, and warns when the next point would be too steep to walk.
2. Press Enter (or Finish in the overlay) to stop.
3. To continue an existing passage later, select it and click Continue Passage on the Build tab. It continues from its free end.

Without an entrance, Draw Passage starts a free passage at the first click.

Good spacing: one point every 6–15 m on straight sections, more points in bends.

3. Shape the passage

Click a point to select it:

• Move handle – drag in any direction. Dragging up or down makes the passage climb or descend.
• Yellow cubes – drag sideways to change the width, up to change the height at this point.
• Yellow outline – the cross-section at this point.
• Dotted line – drops to the ground, to judge height.

On the Selected tab you can also type exact values:

• Position (cave) / Floor Elevation (world Y) – where the point is
• Width (m) / Height (m) – this point’s size. Untick Use Cave Defaults to override; sizes between points blend smoothly.
• Profile – the cross-section shape at this point
• Curve – Auto Smooth (the tool rounds the path) or Manual Curve (shows a green handle you can drag to shape the bend)
• Insert Point After / Delete Point – add or remove points

While you drag, a fast draft preview follows the mouse. The full-quality preview returns when you release.

4. Add rooms

Rooms join passages and give the player space. On the Build tab choose the Room Shape (Square or Round), the Room Template (number of connections) and the Size.

• Square rooms – 2, 3 or 4 connections (Straight, Branch, Hub).
• Round rooms – 2 to 8 evenly spaced connections, in Small (12 m across, 6 m high), Medium (16 m, 6.5 m) and Large (20 m, 8 m). Their connections are called Entry, Port01, Port02 and so on. With an odd number of connections there is no opening straight opposite Entry, so a room inserted into a straight passage makes the passage turn a little.
• Insert Room – select a passage, click Insert Room, hover the passage and click. The room replaces that part of the passage and both halves connect to it. A green ghost shows the room; red means there is not enough passage there, and the message next to the cursor says how much is needed.
• Place Room – places a free room: click the centre, then aim its Entry connection and click. Connect passages to it afterwards.

A selected room has a move handle and a blue rotation ring. The handles follow Unity’s tool: with Rotate (E) only a green rotation ring is shown (drag it to turn the room, Ctrl = 15° steps), Move (W) brings back the arrows. Entrances and crossings work the same way. Smaller / Larger in its action bar switch between the sizes of the same shape and template; connected passages stay connected. Square / Round (in the action bar, and as Shape in the window’s room panel) change the shape of a placed room: it stays in place and every attached passage moves to the new opening that faces its way, so nothing disconnects. The tool picks the preset whose openings line up best with the attached passages (a square 3-way room becomes a round 4-connection chamber, the unused opening is plugged). A shape that has too few openings for the attached passages is greyed out with the reason. Rooms always keep a level floor. Passages take care of height differences.

5. Connect rooms and entrances

Lay out the key places first (entrances and rooms with Place Entrance / Place Room), then join them. Build tab > Connections:

• Connect (A → B) – every free opening and every free passage end becomes a large target in the Scene view. Click A, then B: two openings get a new straight passage; a passage end and an opening – the passage ends in that opening; two passage ends – the passages become one; a passage end and the middle of another passage – they join with a 3-way crossing. The mode stays on for the next pair; Esc drops A, a second Esc leaves the mode. The label shows the distance and slope, and explains why a pair is refused (already connected, too close).
• Auto Connect – joins free openings that face each other (within 60°), are within Max Distance, stay walkable and do not pass through another room; closest and best aligned pairs first. In Connect mode its suggestions are drawn as dotted lines. One Undo step.
• The passage list – every passage as A → B with Edit (select it) and ✕ (delete, Undo restores it).
• Edit a connection – select the passage; on the Selected tab each end has Reassign (pick another opening for A or B in the Scene view) and Disconnect. Open ends have Connect (attach to an opening) and Draw.
• Shape it – a selected passage shows green + markers in the middle of each section. Click one to add a point there; it is selected at once, so drag it to bend, climb or descend the passage.

6. Branches and connections

Click a connection arrow to select it. On the Selected tab:

• Draw Branch – starts a new passage from this connection (also on the Build tab).
• Connect Existing Passage – attaches the open end of another passage to this connection. The list shows how far away each open end is.
• Disconnect – detaches the passage. It keeps its shape and gets an open end.
• Mark as Closed / Mark as Free – a note for yourself. Unused connections are always plugged, so they never leave a hole.

Crossroads and branches from a passage – no room needed:

• Crossroads – draw a passage across another one at about the same height (up to 2 m apart). With Auto Crossroads on (Build tab, under Draw Passage) both are joined there by a 4-way crossing when you finish drawing. Crossings made later (e.g. by moving points) show a Make Crossroad button in the Scene view; Make Crossroads on the Build tab converts all of them at once. The crossing piece is built at the angle the passages actually cross (25°–155°, in 5° steps), so they run straight in; at sharp angles its arms get longer and a rock pillar separates the two tunnels. Pieces for new angles are created automatically in Data/Modules/Crossings.
• Branch from a point – select a point in the middle of a passage. The bar under it offers Branch Left, Branch Right (a 3-way crossing, then you draw the new passage) and 4-Way Crossing (both sides open; draw from them later). The same buttons are on the Selected tab. A crossing needs about 7 m of passage on each side of the point.
• Join a passage while drawing – in Draw Passage, click on another passage (not an opening) to end your passage there with a 3-way crossing. Before the first point, the same click starts a new branch from that passage. Hold Shift to place a normal point over a passage instead.
• Angle – select a crossing, then either drag the green handle at the end of its side arm (a ghost shows the angle, release to apply), click Angle ▾ in its action bar to pick any value, or use ◄ ► (5° per click). Range 25°–155°: for a 4-way the angle between the two passages, for a 3-way the angle of the branch. Connected passages stay attached; if one now bends too tightly you are told which.
• Fit to Passages (in the Angle ▾ menu and on the Selected tab) – the smart option: turns the crossing and sets its angle so its openings point where the connected passages actually go. Draw the passages roughly where you want them, then click it.
• 3-Way / 4-Way – select a crossing to switch it. A 3-way crossing has a wall where the 4-way has its Left opening, so that opening must be free.

7. Passage ends

Select a passage. Under Ends:

• Open – the passage simply stops. Use it while building, or where the passage continues in other geometry.
• Close – seals the end with a rounded cap.
• Draw – continues the passage from that end.
• Disconnect – frees an end that is attached to a room.

8. Climbs and shafts

Drag points up or down to climb. The tool keeps the floor level across the passage on walkable slopes and turns the passage into a vertical shaft when it gets very steep.

• Walkable mode (default) warns about slopes steeper than Walkable Slope (default 30°). Set it to match your character controller.
• Freeform mode accepts steep sections and shafts – for caves the player climbs, falls or flies through.

Both settings are on the Selected tab with nothing selected (Walkability). A shaft needs room to bend: give it about its own height to curve from horizontal to vertical. Fix Path helps when it does not fit.

9. Whole-cave settings

Select the cave object in the Hierarchy. If a point, passage or room is still selected, click ‹ Cave Settings at the top of the Selected tab. With nothing inside the cave selected, the Selected tab shows:

• Name – the cave object’s name
• Passage Defaults – Width, Height and Profile for every point without its own values, and Transition Length, the straight section in front of every opening
• Walkability – Mode and Walkable Slope
• Closures – the End Cap and Connection Plug pieces used for closed ends and free connections

A selected passage can also override width, height and profile for all its points (Size and Shape), and use its own Alternative patch amounts (Local Appearance).