🔨STL Export Settings Guide

Understanding Your Settings: TopoMiller gives you precise control over your 3D terrain models. This guide explains each setting to help you create the perfect topographic relief for CNC carving.

📏Scale Mode

Fit to Size

Scales the longest dimension of your terrain to a target size (default 100mm). Perfect when you need models to fit specific CNC bed dimensions.

Example: A 20km × 15km region scaled to 100mm will produce a 100mm × 75mm model (preserving aspect ratio).

True Scale

Uses a fixed scale ratio (like 1:100,000) for predictable, consistent dimensions across multiple models. Ideal for creating matching sets or comparing different regions at the same scale.

Example: At 1:100,000 scale, a 10km × 10km region will always produce a 100mm × 100mm model (1cm = 1km).

💡 Auto-enables True Z-axis scale to maintain geographic accuracy in all dimensions.

🎯Target Size & Scale Ratios

Target Size (Fit to Size mode)

Specifies the size in millimeters for your model's longest dimension.

Range: 50mm - 300mm
Default: 100mm
Aspect ratio always preserved

Scale Ratio (True Scale mode)

Use the interactive slider to select any scale ratio between 1:10,000 and 1:1,000,000.

Range: 1:10,000 to 1:1,000,000
Logarithmic scale — smooth control across entire range
Real-time preview — dimensions update as you drag
Common values: 1:50k (1cm=500m), 1:100k (1cm=1km), 1:500k (1cm=5km)
Fine-tuning: Choose any custom ratio to fit your needs

⚠️ Size Warning: Models larger than 250mm may not fit on standard CNC beds. The dimension calculator shows warnings for oversized models.

⛰️Relief Height (Vertical Exaggeration)

Looking for Vertical Exaggeration? Relief Height controls both the physical height AND the vertical exaggeration of your terrain. Increasing relief height makes terrain features more dramatic and visible.

Controls the maximum height of terrain features in your model, from the base to the highest peak. This setting directly affects vertical exaggeration - higher values make flat terrain more visible, lower values create subtle relief.

Range & Defaults

• Minimum: 5mm (subtle terrain)
• Default: 12mm (balanced)
• Maximum: 50mm (dramatic relief)

💡 Usage Tips

• Higher values = more dramatic terrain
• Use 20-50mm for flat regions (plains)
• Use 5-15mm for mountains
• Consider your end mill reach

📐 Terrain Type Guide:

• Mountains/Canyons: 5-15mm (natural relief is already dramatic)
• Rolling Hills: 12-25mm (balanced detail)
• Coastal/Flat Areas: 20-50mm (exaggeration needed to see features)

Note: When True Z-axis scale is enabled, relief height is auto-calculated to match your scale ratio for geographic accuracy.

📊Vertical Exaggeration

ℹ️ This setting has been simplified and integrated into Relief Height

Vertical exaggeration is now controlled directly by adjusting the Relief Height slider. Higher relief height values create more dramatic terrain (more exaggeration), while lower values create subtle relief (less exaggeration).

How Relief Height Affects Vertical Exaggeration

5-10mm Relief Height — Subtle exaggeration, best for naturally dramatic terrain (mountains, canyons)
12-20mm Relief Height — Moderate exaggeration, good for rolling hills and general use
25-50mm Relief Height — High exaggeration, essential for flat regions (plains, coastal areas)

💡 Pro Tip: Real-world USGS topographic maps often use 2-3x vertical exaggeration in shaded relief views. You can achieve similar results by using 15-25mm relief height for most terrain types.

Why the change? Combining relief height and vertical exaggeration into a single control makes it easier to understand how your model will look. Instead of juggling two separate values, you simply adjust one slider to control how dramatic your terrain appears.

🧭True Z-Axis Scale

Matches the vertical scale to the horizontal scale for geographically accurate models with no exaggeration.

When to Use

Creating scientifically accurate terrain models
True Scale mode (auto-enabled)
High-relief areas (mountains, canyons)
Professional presentations requiring accuracy

When to Avoid

Very flat terrain (plains, beaches)
Large geographic areas with subtle elevation
When visual drama is more important than accuracy
Display models needing exaggerated features

💡 Pro Tip: Use True Z-axis scale for mountainous regions (Grand Canyon, Rockies) where natural relief is dramatic. For flatter areas (Great Plains, coastal regions), disable True Z-axis scale and increase Relief Height to 25-50mm for better visibility.

🏗️Base Thickness

The solid base platform underneath your terrain, providing structural support for mounting and display.

Thin Base

3-5mm — Minimal profile

Standard Base

5-10mm — Recommended

Thick Base

10-20mm — Heavy duty

Considerations: Thicker bases provide better stability and easier mounting but require deeper CNC cuts and more material.

🛰️Data Source

TopoMiller automatically selects the best elevation data source for your region. The hierarchy prioritizes resolution and coverage.

HIGHEST DETAIL

USGS 1m LiDAR — US Only

Ultra-high resolution LiDAR elevation data with 1-meter resolution. Captures fine terrain details like small ridges, erosion patterns, and cliff faces.

Best for: Small to medium US regions (under 100 km²) where maximum detail is needed. Perfect for canyon walls, mountain peaks, and detailed terrain features.

Coverage: Most of the continental US. Check coverage map →

RECOMMENDED

USGS 10m COG — US Only

High-resolution USGS 3DEP data with 10-meter resolution. Direct cloud access for fast processing. Excellent balance of detail and performance.

Best for: Medium to large US regions. Handles regions up to 2,500 km² efficiently. Great for state parks, mountain ranges, and regional terrain.

GLOBAL

AW3D30 — Worldwide

ALOS World 3D elevation data with 30-meter resolution. High-quality global coverage from 82°N to 82°S latitude.

Best for: International locations, large regional models, and anywhere outside the US. Significantly better quality than older SRTM data.

Source: JAXA via OpenTopography. Learn more →

Fallback: AWS Terrain Tiles are used as a final fallback if other sources are unavailable. This provides 30m SRTM data globally.

Auto Mode (Recommended): TopoMiller automatically selects the best available source: 1m LiDAR for small US regions, 10m COG for larger US areas, and AW3D30 for international locations.

🔲Multi-Tile Export

Split large regions into a grid of tiles for CNC machines or 3D printers with limited bed sizes. Tiles align perfectly when assembled.

Grid Options

Choose 1-4 columns and 1-4 rows (max 16 tiles). Each tile exports as a separate STL in a ZIP file.

File Naming

Files are named by position: tile_1_1.stl (row_column). Row 1 is top, column 1 is left.

Assembly tip: Tiles share identical edge elevations. Use a flat surface as reference when gluing. Consider a backing board for large assemblies.

⚡Quick Reference

🏔️

Mountainous Terrain

True Scale + True Z-axis, 1:100,000, 20-30mm relief

🌄

Rolling Hills

Fit to Size, 15-20mm relief height

🏖️

Coastal/Flat Areas

Fit to Size, 30-50mm relief height (high exaggeration)

📐

Scientific/Educational

True Scale + True Z-axis, 1:50,000 or 1:100,000

🎨

Artistic Display

Fit to Size, 25-50mm relief height for dramatic effect

🔄

Matching Set

True Scale mode, same ratio for all regions

💡 Pro Tips

Use the 3D Preview to see your exact dimensions before exporting
Check the dimension calculator for warnings about oversized models
Start with default settings and adjust based on your first print
Thicker material (2-3 inches stacked baltic birch) creates more impressive models
Consider your CNC bed size when selecting regions