Terrain Heightmap Editing
The terrain heightmap is the foundation of every Unturned™ map. It is the elevation data that defines the shape of the land: the hills players crest, the valleys they traverse, the cliff faces that create tactical height advantage, and the riverbeds that channel water flow. Before any material is painted, before any object is placed, and before any foliage is distributed, the heightmap determines what is possible on the map.
This article is a procedural tutorial covering every heightmap editing tool available in the Level Editor. It documents the five brush modes (raise, lower, smooth, flatten, noise) with step-by-step instructions for each, the brush control parameters (size, strength, falloff), the terrain resolution settings, and the workflow for creating islands, valleys, and mountain ridges. The article also covers heightmap corruption, collider mismatch, and terrain tile seam issues with their diagnostic and resolution procedures. The article assumes the reader is familiar with the Level Editor interface, camera controls, and toolbar layout from the preceding articles.
Prerequisites
- A map created in the Level Editor following Custom Map Creation: Project Setup. The editor must be open and the map must have initialized terrain data.
- Familiarity with the editor toolbar, viewport navigation, and panel layout, covered in Level Editor UI and Navigation.
- A mouse with a scroll wheel. All terrain brush operations depend on scroll-wheel input for brush size adjustment.
- An understanding of the map size and terrain resolution, which are fixed at map creation and cannot be changed after heightmap editing begins.
What you will learn
- How to open the Terrain panel and access the heightmap editing tools.
- How to use each of the five brush modes: raise, lower, smooth, flatten, and noise.
- How to configure brush size, strength, and falloff for different sculpting tasks.
- How to create hills, valleys, cliff faces, and flat building pads.
- How to use noise mode to add natural micro-variation to flat terrain.
- How to work with terrain resolution settings and understand the constraints they impose.
- How to diagnose and resolve heightmap corruption, collider mismatch, and terrain tile seam issues.
Background: how the terrain heightmap system works
The terrain heightmap is a 16-bit grayscale image where each pixel represents the elevation of one point on the terrain surface. The heightmap resolution is fixed at 512 by 512 pixels per terrain tile for all map sizes. A Medium map, which uses a 4 by 4 grid of tiles, has a total heightmap resolution of 2048 by 2048 pixels.
When the heightmap brush is applied, the editor modifies the pixel values in the heightmap image at the brush position. The modified heightmap is rendered on the terrain mesh in real time. When the map is saved, the modified heightmap is written to Level/Terrain/Heightmap.png.
As shown in the flowchart above, the heightmap editing loop is iterative. The modder sculpts, evaluates the result in the viewport, smooths transitions, and saves. There is no undo function for individual brush strokes. The cohort recommendation is to save the map before beginning each sculpting pass so that the previous state can be restored if the pass produces unsatisfactory results.
Opening the Terrain panel
The Terrain panel is the control center for all heightmap and material editing.
Step 1: Open the Terrain panel by clicking the Heightmap icon in the Terrain tools group on the toolbar, or press T.
Step 2: The Terrain panel opens as a floating panel. The panel has three tabs: Heightmap, Materials, and Paint. Ensure the Heightmap tab is selected.
On-screen appearance: The Terrain panel displays the brush mode buttons at the top, the brush parameter sliders in the middle, and the terrain tile selection controls at the bottom. The active brush mode is highlighted.
Brush modes
The Terrain panel's Heightmap tab exposes five brush modes. Each mode modifies the heightmap pixels within the brush radius according to a different algorithm.
Raise mode
Raise mode increases terrain height at the brush cursor position. The amount of height added per stroke is controlled by the Strength slider.
Behavior: Each click or click-drag stroke raises the terrain at the brush position by a value proportional to the Strength setting. If the brush is held in one position, the terrain continues to rise at the configured rate. The shape of the raised area follows the brush falloff profile.
Use cases: Building hills, ridges, elevated terrain features, plateaus, and mountain bases.
On-screen appearance: The terrain rises under the brush, forming a mound centered on the brush cursor. The rate of elevation change is visible as the terrain mesh deforms in real time. A solid circle cursor appears with no special indicator.
Lower mode
Lower mode decreases terrain height at the brush cursor position. The amount of height removed per stroke is controlled by the Strength slider.
Behavior: Each click or click-drag stroke lowers the terrain at the brush position. If the brush is held in one position, the terrain continues to sink at the configured rate.
Use cases: Creating valleys, depressions, riverbeds, excavations, and basins for lakes or ponds.
On-screen appearance: The terrain sinks under the brush, forming a depression centered on the brush cursor. The rate of elevation change is visible in real time.
Smooth mode
Smooth mode averages the height values within the brush radius, reducing sharp transitions between high and low areas.
Behavior: The brush averages the height of each heightmap pixel with the heights of its neighboring pixels within the brush radius. The result is a blurring effect on the terrain surface that softens sharp edges. Multiple passes of the smooth brush produce progressively smoother terrain.
Use cases: Blending harsh edges after raise and lower operations, creating natural-looking terrain contours, softening cliff edges, preparing terrain for road placement.
On-screen appearance: The terrain surface shifts toward a blended average. Sharp edges soften. The brush cursor appears as a solid circle with a dashed border to distinguish it from raise and lower modes.
Flatten mode
Flatten mode sets all height values within the brush radius to the height of the first point the brush touched.
Behavior: The tool is activated in two steps. First, hold Ctrl and click on the terrain at the target height. This sets the reference height to the elevation of the clicked point. Release Ctrl. Second, paint the area to be flattened. All terrain within the brush radius snaps to the reference height.
Use cases: Building foundations, road beds, building pads, flat areas for structures, helipads, and any surface that must be perfectly level.
On-screen appearance: Terrain within the brush area snaps to the target height immediately. A crosshair appears at the reference height point to indicate where the target height was set. The brush cursor shows no additional indicators.
Noise mode
Noise mode adds random height variation within the brush radius using a Perlin noise function.
Behavior: The brush applies random elevation changes to heightmap pixels within the brush radius. The amplitude of the noise is controlled by the Strength slider. The frequency of the noise is fixed by the engine and cannot be adjusted.
Use cases: Adding surface texture to flat terrain, simulating natural micro-variation, breaking up the uniform flatness of plateaus and valley floors, creating rough or rocky terrain surfaces.
On-screen appearance: The terrain surface develops a grainy texture as micro-variation is added. The effect is subtle at low strength (0.01-0.02) and becomes more pronounced at higher strength values. The brush cursor appears as a solid circle with a stippled fill pattern.
Visual reference for brush modes
| Mode | Brush cursor appearance | Terrain behavior |
|---|---|---|
| Raise | Solid circle, no special indicator | Terrain rises under the cursor |
| Lower | Solid circle, no special indicator | Terrain sinks under the cursor |
| Smooth | Solid circle with dashed border | Terrain surface shifts toward blended average |
| Flatten | Crosshair at reference height point | Terrain snaps to reference height |
| Noise | Solid circle with stippled fill | Terrain develops grainy micro-variation |
Brush control parameters
The Terrain panel exposes three controls that apply to all brush modes:
| Control | Range | Default | Description |
|---|---|---|---|
| Size | 1-200 | 40 | The radius of the brush in terrain units. Larger sizes cover more area per stroke. |
| Strength | 0.01-1.0 | 0.05 | The effect intensity per stroke. Higher values produce more elevation change per click or drag. |
| Falloff | 0.0-1.0 | 0.5 | The edge softness of the brush. Higher values produce a harder edge; lower values produce a gradual blend at the brush boundary. |
Size selection guidance
| Brush size | Use case |
|---|---|
| 1-10 | Micro-detail sculpting: erosion traces, rock shelves, minor slope variation |
| 10-30 | Small features: individual hillocks, boulder bases, path contours |
| 30-60 | Medium features: hills, ridgelines, cliff faces, lake basins |
| 60-120 | Broad features: macro elevation zones, mountain bases, valley floors |
| 120-200 | Very broad elevation changes: terrain mass adjustments, large plateaus |
Strength selection guidance
| Strength range | Use case |
|---|---|
| 0.01-0.02 | Micro-detail passes, very fine adjustments |
| 0.02-0.05 | Meso terrain passes, gradual elevation changes |
| 0.05-0.15 | Macro elevation passes, broad landscape shaping |
| 0.15-0.5 | Aggressive sculpting, rapid elevation changes |
| 0.5-1.0 | Extreme sculpting (use with caution; risk of heightmap corruption) |
Falloff selection guidance
| Falloff value | Effect |
|---|---|
| 0.0-0.3 | Very soft edge. The brush blends gradually into the surrounding terrain. Use for natural landscape features. |
| 0.3-0.6 | Medium edge. The brush has a noticeable transition zone. Use for general sculpting. |
| 0.6-0.8 | Hard edge. The brush boundary is distinct. Use for building pads, cliff edges, road cuts. |
| 0.8-1.0 | Very hard edge. The brush boundary is sharp. Use for excavations, terraces, and engineered terrain features. |
Step-by-step: sculpting a hill
Step 1: Open the Terrain panel and ensure the Heightmap tab is selected.
Step 2: Set the brush mode to Raise. The Raise button is the first icon in the brush mode row.
Step 3: Set the brush Size to 60 and Strength to 0.05. These values produce a broad, gentle elevation change appropriate for a hill.
Step 4: Position the brush cursor at the intended hill center. Left-click and hold, then move the mouse in small circles to distribute the elevation change. The terrain rises under the brush.
Step 5: After 20 to 30 strokes at the same position, the terrain should show a visible mound approximately 10 to 15 units high. Continue applying strokes until the desired height is reached.
Step 6: Switch to Smooth mode with Size 40 and Strength 0.3. Paint around the base of the hill to blend the transition into the surrounding flat terrain.
Step 7: The result is a smooth, natural-looking hill. Save the map.
On-screen appearance: During Raise mode strokes, the terrain mesh deforms in real time, rising in a mound shape. During Smooth mode strokes, the sharp edges at the hill base soften as the height values are averaged.
Step-by-step: creating a valley or riverbed
Step 1: Switch the brush mode to Lower.
Step 2: Set the brush Size to 30 and Strength to 0.03. A smaller brush creates a more defined channel.
Step 3: Click and drag along the intended path of the valley or river. The terrain sinks under the brush, forming a linear depression.
Step 4: For a wider valley, increase the brush Size to 60 and make additional passes along the same path. The depression widens with each pass.
Step 5: Switch to Smooth mode with Size 50 and Strength 0.2. Paint along the edges of the depression to create a natural bank transition.
Step 6: The result is a valley or riverbed with a defined channel and smooth banks. Save the map.
On-screen appearance: The terrain sinks along the dragged path, forming a continuous depression. The depression deepens with each pass of the brush.
Step-by-step: using Flatten mode for a building pad
Step 1: Ensure the terrain at the intended building location is roughly level. Use Raise or Lower mode to bring the general area to approximately the correct elevation.
Step 2: Hold Ctrl and click on the terrain at the exact height you want the building pad to be. A crosshair appears at the clicked point.
Step 3: Release Ctrl. The Flatten mode is now armed with the reference height.
Step 4: Set the brush Size to match the building footprint. For a standard house, use Size 20 to 30. Set Strength to any value (strength does not affect Flatten mode).
Step 5: Paint the area to be flattened. The terrain within the brush radius snaps to the reference height.
Step 6: Repeat step 5 for adjacent areas if the building pad is larger than the brush size.
Step 7: The result is a flat, level surface suitable for building placement. Save the map.
On-screen appearance: The terrain surface immediately becomes level at the reference height within the brush area. The transition to the surrounding terrain may be sharp. Use Smooth mode to blend the edges after flattening.
Step-by-step: using Noise mode for terrain texture
Step 1: Switch the brush mode to Noise.
Step 2: Set the brush Size to 80 and Strength to 0.02. The low strength prevents excessive height variation.
Step 3: Paint across large areas of flat terrain such as fields, plateaus, and valley floors. The noise adds 0.1 to 0.5 unit height variations that break up the uniform flatness of the terrain surface.
Step 4: After the noise pass, the terrain looks less artificial because the micro-variation simulates natural erosion and soil movement.
Step 5: If the noise is too subtle, increase Strength to 0.05 and make another pass. If the noise is too pronounced, switch to Smooth mode at low strength to reduce the variation.
On-screen appearance: The terrain surface develops a fine-grained texture as the noise is applied. The effect is subtle at Strength 0.02 and becomes more pronounced at higher values.
Creating islands
Creating an island on an Unturned map requires setting the terrain height below the water plane so that the surrounding area is submerged, leaving only the raised area above water.
Step 1: Use Raise mode with Size 100 and Strength 0.1 to create a broad mound in the center of the intended island location. Raise the mound to approximately 15 to 20 units above the surrounding terrain.
Step 2: Use the Smooth brush at Size 60 and Strength 0.3 to shape the island's slopes into a natural profile. Steeper slopes on one side and gentler slopes on the other produce a more realistic island shape.
Step 3: Use the Lower brush at Size 120 and Strength 0.1 around the island to ensure the surrounding terrain is below the water plane elevation. The water plane elevation is set in the Water panel.
Step 4: Verify that the island's highest point is above the water plane and that the surrounding terrain is below it. The water plane covers the full map extent at the configured elevation.
Step 5: Save the map. Open the Water panel and verify that the water plane elevation is between the island's base elevation and its peak elevation.
Terrain resolution settings
The terrain resolution is fixed at map creation and cannot be changed without recreating the map. The resolution is 512 by 512 heightmap pixels per terrain tile for all map sizes.
Resolution constraints
The fixed resolution imposes practical constraints on heightmap detail:
- A Tiny map (1 tile) has 512 by 512 heightmap pixels total.
- A Small map (2 by 2 tiles) has 1024 by 1024 heightmap pixels total.
- A Medium map (4 by 4 tiles) has 2048 by 2048 heightmap pixels total.
- A Large map (8 by 8 tiles) has 4096 by 4096 heightmap pixels total.
- An Insane map (16 by 16 tiles) has 8192 by 8192 heightmap pixels total.
Each heightmap pixel represents the elevation at one point on the terrain surface. The horizontal distance between adjacent heightmap pixels depends on the map size. On a Medium map, each pixel represents approximately 4 units of terrain distance.
Practical detail limit
Because the heightmap resolution is 512 by 512 per tile, features smaller than one heightmap pixel cannot be represented. The minimum feature size is approximately 4 units on a Medium map. Brush strokes smaller than this range are aliased, producing stair-step artifacts rather than smooth contours.
If the terrain looks pixelated after fine-detail sculpting, the brush strokes are smaller than one heightmap texel, and the detail cannot be represented at the current resolution.
Multi-tile terrain editing
Maps larger than Tiny use multiple terrain tiles arranged in a grid. Each tile has its own heightmap, splatmap, and material configuration.
Tile selection
In the Terrain panel, the tile selection control at the bottom of the panel allows selecting which tile to edit. The control shows a grid of tiles with the currently selected tile highlighted. Click a tile in the grid to select it. The viewport focuses on the selected tile.
Editing across tile boundaries
Brush strokes that cross tile boundaries affect only the currently selected tile. The adjacent tile is not modified. To edit terrain across a tile boundary, select each tile in turn and apply the brush to the region near the boundary.
Failure mode: seams between terrain tiles
A visible seam or height gap may appear at the boundary between two adjacent terrain tiles. This appears as a vertical wall or drop where two terrain tiles meet, with one tile slightly higher or lower than its neighbor at the shared edge.
Resolution: Select the affected terrain tile and use the Smooth brush at maximum size along the tile edge, positioned so that the brush straddles both tiles. The smooth operation averages the heights across the seam. For persistent seams, use the Flatten tool to set both tiles to the same height at the seam boundary.
Heightmap corruption and fixes
Heightmap corruption is one of the most disruptive issues in terrain editing. It can occur through excessive brush strength, editor crashes during save, or file system errors.
Identifying heightmap corruption
The terrain suddenly appears as a jagged wall of spikes or as a completely flat plane after a brush operation. The affected area shows terrain that either shoots upward into a spike formation or drops into a bottomless pit. The surrounding terrain may tear at the boundary between the corrupted area and the valid heightmap.
Root cause
The most common cause is applying an extremely high Strength value (above 0.8) with a large brush size, which produces height values outside the valid range. The heightmap stores values as 16-bit unsigned integers with a valid range of 0 to 65535. Values outside this range produce wrap-around artifacts that manifest as spikes or pits.
A second cause is an editor crash during a save operation that was writing the heightmap file. The partial write produces a truncated or corrupted Heightmap.png file.
Resolution
If the corruption occurred during the current editor session and the map has not been saved since the corruption, close the editor without saving. The heightmap on disk is still valid. Reopen the map and test the brush settings on a small area before repeating the operation.
If the map was saved after corruption, the corrupted heightmap is on disk. Restore from the most recent backup of the Level/Terrain/ directory. If no backup is available, the terrain must be re-sculpted from scratch.
Prevention
- Never set the brush Strength above 0.5 during normal sculpting. Values above 0.5 are for extreme operations only.
- Save the map before beginning each sculpting pass.
- Keep a backup of the
Level/Terrain/directory from the previous session.
Failure mode: collider mismatch
After sculpting, some areas of the terrain may appear visually correct but players or zombies fall through the surface. This is a collider mismatch between the rendered terrain mesh and the physics collider.
What it looks like: The terrain renders correctly with material layers and detail, but the player character falls below the surface and stands at a lower elevation, or the character's feet clip through the visible terrain.
Resolution: The collider mismatch is resolved by selecting the terrain object in the editor and re-baking the collider. This operation is triggered by toggling the terrain collider checkbox in the Terrain panel off and on again. After re-baking, save the map.
Failure mode: heightmap export for reference
The heightmap file can be found at Level/Terrain/Heightmap.png. This file is 16-bit grayscale. Most image editors require explicit 16-bit mode to read it correctly. The file can be opened in image editing software for analysis or reference, but editing it externally and replacing the file is not supported and will likely cause loading failures.
Terrain editing workflow for complete maps
The 57 Studios™ cohort authors heightmaps in three passes, following a macro-to-micro workflow that produces natural-looking terrain with minimal rework.
Pass 1: Macro elevation
Use a large brush (Size 80 to 120) at low strength (0.05) to establish the major elevation regions of the map. This pass determines which zones are highlands, which are lowlands, and where major rivers and valleys will run. This pass should take no more than 20 to 30 minutes and should produce a readable elevation silhouette when viewed from above.
Pass 2: Meso terrain
Reduce brush size to 30 to 60 and strength to 0.02 to 0.05. Define the hills, ridgelines, cliff faces, and lake basins. The goal of this pass is to produce the playable terrain shapes: the hills players will crest, the valleys they will move through, and the cliff edges that create height advantage.
Pass 3: Micro detail
Reduce brush size to 5 to 20 and strength to 0.01 to 0.02. Add erosion traces, rock shelves, minor slope variation, and riverbank irregularity. This pass is where terrain feels handcrafted rather than programmatically generated. The Smooth mode is particularly useful here to blend sharp transitions from earlier passes.
Frequently asked questions
How long does it take to sculpt the heightmap for a Medium map?
The 57 Studios™ cohort benchmark for a Medium map heightmap is 2 to 4 hours spread across three sculpting passes. The macro elevation pass takes 20 to 30 minutes. The meso terrain pass takes 1 to 2 hours. The micro detail pass takes 30 minutes to 1 hour. First-time modders should budget 4 to 8 hours for the same work.
Can I use a graphics tablet or stylus for heightmap sculpting?
Yes. The editor accepts input from any device that emulates a mouse. A graphics tablet with pressure sensitivity provides finer control over brush strength because the pressure maps to the brush intensity. The cohort recommendation is to map the tablet pen pressure to the brush strength slider for natural-feeling sculpting.
Why does the terrain appear completely flat when I first open a newly created map?
A newly created map has a flat heightmap at elevation 0. The terrain appears as a flat plane because no sculpting has been performed yet. This is the expected state. Begin sculpting with the Raise brush to create the first elevation features. The flat terrain is the blank canvas for all subsequent sculpting work.
What is the difference between the heightmap and the splatmap?
The heightmap stores elevation data as grayscale pixel values. The splatmap stores material layer blend weights as multi-channel pixel values. The heightmap determines the shape of the terrain. The splatmap determines the visual texture painted on that shape. They are independent data sets stored in separate files.
Why does my brush produce no visible effect on the heightmap?
The brush may be active but the Strength setting is too low to produce a visible change in a single stroke. Increase the Strength to 0.1 and apply the brush in a small, contained area. If the terrain still does not change, verify that the Terrain panel's Heightmap tab is active and that the brush mode is not set to a mode that does not match the intended operation.
How do I create a flat area on a slope?
Use the Flatten mode. First, hold Ctrl and click on the terrain at the highest point of the intended flat area to set the reference height. Then paint the area to be flattened. The terrain snaps to the reference height, creating a level platform on the slope. Use Smooth mode to blend the edges of the platform into the surrounding slope.
What is the maximum terrain height I can sculpt?
The heightmap stores elevation as a 16-bit unsigned integer with a valid range of 0 to 65535. In world units, the maximum terrain height is approximately 1024 units above the base elevation. Values above this range produce wrap-around artifacts that damage the heightmap.
Why does my terrain look pixelated after fine-detail sculpting?
The terrain heightmap resolution is fixed at 512 by 512 pixels per tile. Features smaller than one heightmap pixel cannot be represented. If the brush strokes are smaller than the distance between heightmap pixels, the detail is aliased and appears as stair-step artifacts. To avoid pixelation, use larger brush sizes and work at a zoom level where the heightmap grid is not visible.
Can I import an external heightmap image into the editor?
The Level Editor does not support direct import of external heightmap images. Heightmap data can only be authored through the sculpting brushes. If an external heightmap must be used, it must be imported into a Unity Terrain component first and then the resulting terrain data must be packaged for the map.
How do I fix a seam between two terrain tiles?
Select the affected terrain tile and use the Smooth brush at maximum size along the tile edge, positioned so that the brush straddles both tiles. The smooth operation averages the heights across the seam. For persistent seams, use the Flatten tool to set both tiles to the same height at the seam boundary.
What causes the terrain to suddenly shoot up into spikes?
Applying an extremely high Strength value (above 0.8) with a large brush size produces height values outside the valid range of the heightmap. The resulting wrap-around in the 16-bit integer storage creates spike formations. The fix is to close the editor without saving and reopen the map to restore the valid heightmap from disk.
Why do players fall through the terrain after sculpting?
The terrain collider may be out of sync with the visual mesh after extensive sculpting. Select the terrain object in the editor and re-bake the collider by toggling the terrain collider checkbox in the Terrain panel off and on again. After re-baking, save the map.
Can I undo a heightmap brush stroke?
The Level Editor does not have an undo function for heightmap brush strokes. Once a stroke is applied, the heightmap pixels have been modified in memory. The only way to revert a stroke is to apply an inverse stroke (lower to undo a raise, raise to undo a lower) or to reload the map from the last save.
Best practices
- Save the map before beginning each sculpting pass. If the pass produces unsatisfactory results, reload the map to restore the previous state.
- Use the macro-to-micro workflow: start with large brushes and low strength for broad elevation, then progressively reduce brush size for detail.
- Use Smooth mode after every Raise or Lower pass to blend sharp transitions. Natural terrain has few perfectly sharp edges.
- Never set brush Strength above 0.5. The risk of heightmap corruption above this threshold is not worth the time saved.
- Keep a backup of the
Level/Terrain/directory at the end of each sculpting session. - Test terrain from a player's perspective (ground-level camera position) after each sculpting pass. What looks correct from above may look unnatural from ground level.
- Use Flatten mode for building pads and road beds before placing structures. Objects placed on un-flattened terrain may float or clip.
- Use Noise mode sparingly on natural terrain. Excessive noise produces a lumpy surface that looks artificial.
- Verify multi-tile seams after every sculpting pass on Large and Insane maps.
- Document the date and work completed for each backup so that the correct backup can be identified during recovery.
Advanced considerations
Heightmap data structure
The heightmap PNG file uses 16-bit grayscale encoding where each pixel value represents the terrain height at that point. The value range is 0 to 65535, which maps to a world-space height range of 0 to approximately 1024 units. The encoding is linear: pixel value 32768 corresponds to a world-space height of approximately 512 units.
The heightmap file format is standard PNG with 16-bit grayscale color mode. Most image editors can open and display the file, but the 16-bit mode must be explicitly selected in editors that default to 8-bit mode.
Terrain deformation and performance
Heavily sculpted terrain with extreme elevation changes produces more triangles in the terrain mesh than flat terrain. The terrain system uses a level-of-detail algorithm that reduces triangle count at distance, but very steep terrain with frequent elevation changes can impact rendering performance. The cohort recommendation is to avoid extreme elevation gradients unless the map's design requirements specifically call for them.
Heightmap restoration from texture data
If the heightmap PNG is corrupted but the terrain material splatmap is intact, a skilled modder can reconstruct a rough approximation of the heightmap by analyzing the splatmap's layer distribution (certain layers tend to appear at specific elevations). This is an advanced recovery technique and is not recommended as a primary recovery strategy. The cohort recommendation is to maintain regular backups of the Level/Terrain/ directory.
Appendix A: Brush mode quick reference
| Mode | Keyboard shortcut | Primary use | Recommended strength |
|---|---|---|---|
| Raise | 1 (when Terrain panel active) | Building hills, ridges, elevated terrain | 0.02-0.15 |
| Lower | 2 | Creating valleys, depressions, riverbeds | 0.02-0.15 |
| Smooth | 3 | Blending transitions, softening edges | 0.1-0.4 |
| Flatten | 4 | Building pads, road beds, flat surfaces | Does not use strength |
| Noise | 5 | Micro-variation, surface texture | 0.01-0.05 |
Appendix B: Diagnostic table for heightmap issues
| Symptom | Root cause | Resolution |
|---|---|---|
| Terrain appears as jagged spikes | Strength above 0.8 produced out-of-range values | Close without saving; restore from backup if saved |
| Terrain is completely flat after opening | Heightmap.png corrupted or missing | Restore Level/Terrain/ from backup |
| Players fall through terrain | Collider mismatch after sculpting | Re-bake collider in Terrain panel |
| Visible seam between terrain tiles | Adjacent tiles at different heights | Use Smooth brush across tile boundary |
| Pixelated terrain after fine sculpting | Brush strokes smaller than heightmap resolution | Use larger brush sizes |
| Brush produces no visible effect | Strength too low or wrong tab selected | Increase Strength to 0.1; verify Heightmap tab is active |
| Noise pass produced lumpy surface | Strength too high for current terrain scale | Use Smooth brush to reduce variation |
| Flatten mode not working | Reference height not set | Hold Ctrl and click to set reference height before painting |
| Multi-tile brush only affects one tile | Only one tile selected in Terrain panel | Select each tile and apply brush separately |
| Terrain disappears at camera distance | Render distance set too low in editor settings | Increase render distance in editor settings menu |
Appendix C: External references
- Smartly Dressed Games official modding documentation - the authoritative reference for terrain editing controls and heightmap configuration.
- Unturned on Steam - the Unturned store page and community hub.
- Custom Map Creation: Project Setup - the prerequisite article covering map size selection and initial terrain configuration.
Cross-references
- Terrain Material Painting - the next article in this series; covers terrain material layer creation and painting on the sculpted heightmap.
- Level File Management - the previous article in this series; covers save operations and backup strategies for heightmap files.
- Level Editor UI and Navigation - the first article in this series; covers viewport navigation and panel layout.
- Object Browser and Inspector - the third article in this series; covers object placement on sculpted terrain.
Authoring checklist
Before concluding that terrain heightmap editing is complete for a given map project, confirm the following:
- [ ] All five brush modes (raise, lower, smooth, flatten, noise) have been tested and understood
- [ ] Brush size, strength, and falloff parameters are configured appropriately for each task
- [ ] Macro elevation pass is complete with major highland and lowland zones established
- [ ] Meso terrain pass is complete with identifiable hills, valleys, and ridges
- [ ] Micro detail pass is complete with erosion traces and slope variation
- [ ] Smooth pass has been applied at all major transitions
- [ ] Flatten mode has been used for building pads and road beds
- [ ] Multi-tile seams are smooth (for Small, Medium, Large, and Insane maps)
- [ ] The map has been saved after the sculpting pass
- [ ] A backup of the Level/Terrain/ directory exists from the previous session
- [ ] Terrain heightmap resolution constraints are understood
- [ ] The terrain appears natural from ground-level camera position
Document history
| Version | Date | Author | Notes |
|---|---|---|---|
| 1.0 | 2026-07-26 | 57 Studios | Initial publication. Split from Level Editor Fundamentals and Terrain and Environment Editing into standalone depth treatment. |