Walk the caves before you build one

Both demo levels are nearly empty on purpose — a launcher actor and a PlayerStart. Everything you see is generated when you press Play, so they open instantly and never ask you to rebuild lighting.

Interactive tour — walk it

/InstantOrganicCaves/Maps/IOC_InteractiveDemo

Tools › Instant Organic Caves › Open Interactive Demo, then Play. Or the Setup Wizard's Open Interactive Demo button.

Showcase — watch it

/InstantOrganicCaves/Maps/IOC_DemoMap

Tools › Instant Organic Caves › Open Demo Map, then Play: a captioned camera flythrough of eight cave sections.

The tour holds you still for the second it takes to build, under a Generating caves… caption, then drops you at the entrance facing down the path.

Four cave actors make the whole route — two tunnels, and two solid blocks with rooms carved out of them — joined through passages carved to fit each tunnel's mouth. Each zone captions itself the first time you walk in: what the feature is, how you would use it, and that cave's live generation numbers.

01 · The Mouth

Zone 1

The Mouth

A limestone tunnel, lit warm at the entrance. It is one AIOCProceduralActor dropped into the level with a preset applied — the same thing you place yourself.

Feature: the drop-in cave actor and the Large Tunnel preset; the CaveStyleTexture parameter giving it a limestone skin.

Look up: the stalactites are a scatter layer on ceiling faces only.

02 · The Winding Run

Zone 2

The Winding Run

The tunnel bends left and right as it climbs, because it follows a spline. Midway the passage opens out — the same actor, reshaped by a biome volume that overrides its radius, wall and noise inside a box, easing in over ten metres.

Feature: spline tunnels (bUseSpline) and AIOCBiomeVolume with BlendDistance.

Watch the walls pull back as you walk in, and close again as you leave.

03 · Crystal Gallery

Zone 3

Crystal Gallery

A vaulted hall under a dome, with an alcove to one side. The rock here is a solid block; the hall, the dome and the passages in and out are carving components. Crystals, stalactites, stalagmites and geodes are five scatter layers, each confined to a slope range.

Feature: UIOCCarvingComponent (capsule hall, sphere dome) and DecorationLayers with MinSlopeZ / MaxSlopeZ.

The green glow ahead is the next tunnel, seen end-on through the exit passage.

04 · Alien Hive

Zone 4

Alien Hive

Walls folded into organic, hive-like shapes, veined green. One slider does it: domain warp bends the noise field before the tunnel reads it.

Feature: the Alien Hive preset and DomainWarpIntensity, with the alien rock texture.

Compare the wall shapes with the smooth limestone of zone 1 — same generator.

05 · Strata Canyon

Zone 5

Strata Canyon

The last stretch of the same tunnel, lit amber, where the rock breaks into horizontal bands. A second biome volume switches terrace steps on for this stretch only.

Feature: TerraceSteps, applied by a biome volume rather than a second actor.

Ahead, the path drops into the Forge.

06 · The Forge

Zone 6

The Forge

A hall shaped entirely by carving components: a capsule hall and a capsule vault across it, a sphere dome, a squared-off box niche and a capsule chimney. Then it is your turn — a crosshair appears; aim at the rock and left-click to carve.

Feature: every carve shape, and runtime carving through CarveAtLocation, rebuilt in the background with collision.

Carve a pocket in a wall, then walk into it. Only the Forge accepts carves: it carries the IOC_PlayerCarvable tag.

→ Infinite Depths

The portal

Infinite Depths

Walk into the blue crystal by the Forge's far wall. An AIOCStreamingManager takes you to a tunnel it builds chunk by chunk around you and unloads behind you. Keep walking; it does not end.

Feature: streaming, with world-space noise keeping every chunk seam closed, and player coupling that holds you until the floor under you exists.

Each works in any level from the console (~) or Tools › Instant Organic Caves, and each cleans up after itself with IOC.ClearAllDemos.

For a 60–90 second video, use the capture showcase: eight sections, polished captions, no debug text, no external asset paths. The shipped IOC_DemoMap already runs it; or open the Setup Wizard and press Create Starter Level to make /Game/IOC_Showcase with its own launcher.

For the tour, let it walk itself: IOC.TourAutopilot takes the whole route with a steered camera, carves the Forge wall and goes through the portal. For perfectly smooth footage, run the map standalone with a fixed timestep and Unreal's frame dump, then assemble the frames:

UnrealEditor.exe <project> /InstantOrganicCaves/Maps/IOC_InteractiveDemo -game -windowed -ResX=1600 -ResY=900 -benchmark -fps=30 -dumpmovie -IOCTourAutopilot -IOCTourAutopilotQuit -IOCTourNoCaptions

The log prints the frame at which each zone begins, for timing titles. Leave out -IOCTourNoCaptions to keep the in-game captions.

Walk the tour first — it is the demo — then open the editor and show how each thing you just saw is set.

1. Walk the tour

   “Four cave actors, built live in about a second. Six features, one walk.”

   Open Interactive Demo, press Play, walk to the Forge, carve a wall, take the portal.

2. Drop in a cave

   “This is all it takes to start.”

   Place BP_IOC_Cave, cycle CavePreset through Large Tunnel, Tight Crawl, Open Cavern, Alien Hive, Canyon Strata.

3. Draw the route

   “Spline mode lets you author the cave's path instead of accepting one.”

   Enable bGenerateTunnel and bUseSpline; drag spline points.

4. Change a region

   “Local overrides without a second actor.”

   Place an IOCBiomeVolume, override TunnelRadius, set BlendDistance to a few metres.

5. Guarantee space

   “Carving components guarantee rooms, doors and gameplay beats.”

   Add a UIOCCarvingComponent (sphere, box or capsule), adjust its falloff.

6. Dig at runtime

   “And the player can dig.”

   Call CarveAtLocation, or turn on bEnableCaveCarving on AIOCCharacter and tag the cave IOC_PlayerCarvable.

7. Dress it

   “Eight props ship with the plugin, so a furnished cave needs no art.”

   Add SM_IOC_Stalactite at slope −1.0 to −0.6 with bAlignToNormal, then SM_IOC_Rock_B at 0.7 to 1.0 on the floor.

8. Materials

   “UVs and smart vertex colours are generated for you.”

   Toggle bGenerateSmartColors, adjust TextureTiling, swap CaveStyleTexture.

9. Stay fast

   “Async, LOD, and numbers you can read.”

   Enable LOD; show LastGenerationTimeSeconds, voxel and triangle counts.

10. Freeze it

    “When it is final, bake it.”

    Bake to Static Mesh; show the asset under /Game/IOC_Baked.

• Tunnels between two points or along splines, with open ends; spline networks fuse into one system.
• Solid-rock caves from layered noise, and cellular-automata caves through the IOC Voxel Core PCG node.
• Async generation off the game thread, with cancellation, a voxel cache and coalesced carve rebuilds.
• Five presets: Large Tunnel, Tight Crawl, Open Cavern, Alien Hive, Canyon Strata.
• Domain warp and terrace steps for the stranger shapes.
• Smoothing (SmoothIterations) for organic surfaces.
• Smart vertex colours for floor / wall / ceiling blends, and generated UVs with TextureTiling.
• Scatter layers with slope filters and optional Poisson spacing, using eight shipped props — no third-party art.
• LOD meshes with a distance switch and voxel-size multiplier.
• Carving: sphere, box and capsule components with falloff, runtime CarveAtLocation, and opt-in player carving.
• Biome volumes overriding noise, radius, wall and terraces locally, from a brush or a box, with blending.
• Streaming chunks around players, seam-free, with player coupling.
• Networking: server-authority generation, delta-replicated carve history, late-join catch-up.
• Bake to static mesh, with optional Nanite and generated LOD.
• Complex-as-simple collision on the generated mesh, cooked once per build.
• Live metrics: generation time, voxels, triangles, scatter instances.
• Setup Wizard: five guided steps, readiness checks, a voxel budget, undo.
• Two demo maps, the demo commands and a clean-up command that leaves no residue.