# DEM (Elevation)

## Overview: The Foundation of Terrain

The Digital Elevation Model (DEM) serves as the **fundamental terrain foundation** for your Farming Simulator map. Every hill, valley, slope, and elevation change is precisely defined by this critical component.

**Core Concept**: A DEM is essentially a 2D grid where each cell contains a height value, creating a digital representation of real-world topography that the game engine transforms into 3D terrain.

## Technical Specifications

### File Requirements

| Game Version | Image Dimensions                  | File Path                    | Data Format |
| ------------ | --------------------------------- | ---------------------------- | ----------- |
| **FS25**     | (map\_size + 1) × (map\_size + 1) | `map_directory/data/dem.png` | 16-bit PNG  |

**Data Structure:**

* **Channels**: Single channel (grayscale)
* **Data Type**: `uint16` (unsigned 16-bit integer)
* **Value Range**: 0 to 65,535 (2^16 possible elevation levels)
* **Color Depth**: 16-bit for maximum terrain detail precision

### Dimension Examples

**FS25 Standard Sizes:**

* 2048m map → 2049×2049 DEM
* 4096m map → 4097×4097 DEM
* 8192m map → 8193×8193 DEM
* 2048m map → 1025×1025 DEM
* 4096m map → 2049×2049 DEM

## Height Scale System

### Understanding Height Conversion

**The Challenge**: DEM pixels store values 0-65,535, but real-world elevations can exceed 8,000 meters. How does this work?

**The Solution**: The `heightScale` parameter acts as a **conversion multiplier** that transforms pixel values into real-world heights.

### Height Scale Configuration

**Default Value**: 255 (in Giants Editor maps) **Maximum Terrain Height**: `65,535 × (heightScale ÷ 65,535) = heightScale meters` **With Default Settings**: Maximum possible elevation = 255 meters

**Example Calculations:**

```
heightScale = 255  → Max height: 255m
heightScale = 512  → Max height: 512m
heightScale = 1000 → Max height: 1000m
```

### Practical Height Scale Selection

**For Flat Terrain (plains, farmland)**: 128-255m **For Moderate Hills**: 256-512m **For Mountain Regions**: 513-1000m+ **For Extreme Terrain**: 1000m+ (with performance considerations)

### Giants Editor Configuration

1. **Open Map**: Load your map in Giants Editor
2. **Select Terrain**: Choose terrain object in Scenegraph
3. **Terrain Tab**: Navigate to Attributes → Terrain
4. **Set heightScale**: Enter your calculated value
5. **Apply Changes**: Save and reload map (File → Reload)

## Units Per Pixel System

### Spatial Resolution Control

The `unitsPerPixel` parameter defines the **terrain resolution** by specifying how many meters each DEM pixel represents.

**Game Version Defaults:**

* **Available**: `unitsPerPixel = 1` (1 meter per pixel - highest detail)

### Resolution Impact

**Higher Resolution (unitsPerPixel = 1)**:

* ✅ Maximum terrain detail and precision
* ✅ Sharp elevation transitions and fine features
* ⚠️ Larger file sizes and longer processing times

**Lower Resolution (unitsPerPixel = 2+)**:

* ✅ Faster processing and smaller files
* ✅ Suitable for large, gradually changing terrain
* ⚠️ Less detailed elevation features

### Custom Resolution Configuration

1. **Access Settings**: Giants Editor → Terrain → Attributes
2. **Modify unitsPerPixel**: Set integer value (1, 2, 4, etc.)
3. **Recalculate DEM Size**: Adjust DEM image dimensions accordingly
4. **Test Results**: Reload and verify terrain quality

## Advanced Optimization Strategies

### Terrain Quality vs Performance

**Maximum Quality Setup**:

* `unitsPerPixel = 1`
* `heightScale = terrain-appropriate value`
* Full-resolution DEM with detailed elevation data

**Balanced Performance Setup**:

* `unitsPerPixel = 2`
* `heightScale = 512`
* Moderate resolution suitable for most use cases

**Large Map Optimization**:

* `unitsPerPixel = 4`
* Focus on broad terrain features rather than fine detail
* Ideal for 16×16km maps with performance constraints

### Professional Workflow

1. **Analyze Source Terrain**: Study your real-world elevation data
2. **Calculate Height Range**: Determine minimum to maximum elevation difference
3. **Set Height Scale**: Choose value that accommodates your terrain range with headroom
4. **Configure Resolution**: Balance detail needs with performance requirements
5. **Generate & Test**: Create DEM and verify terrain quality in Giants Editor
6. **Iterative Refinement**: Adjust parameters based on visual and performance results

**Pro Tip**: Always maintain some headroom in your height scale to accommodate manual terrain sculpting in Giants Editor without reaching the maximum elevation limit.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://maps4fs.gitbook.io/docs/map-components/dem.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.