snow_trail/blender/scripts

Blender Export Scripts

Python scripts for generating textures and heightmaps from Blender terrain meshes.

Prerequisites

• Blender 5.0+
• Terrain mesh object (default name: "TerrainPlane")

Scripts

generate_heightmap.py

Bakes EXR heightmap from terrain mesh using Blender's render system.

Output: textures/terrain_heightmap.exr (R32Float single-channel)

Usage:

# In Blender's Scripting workspace - just run the script!
# It will automatically find TerrainPlane and bake to textures/terrain_heightmap.exr

Or run from command line:

blender terrain.blend --background --python scripts/generate_heightmap.py

Custom parameters:

from generate_heightmap import bake_heightmap

bake_heightmap(
    terrain_obj=bpy.data.objects["TerrainPlane"],
    resolution=1000,
    output_path="path/to/output.exr"
)

generate_normal_map.py

Generates normal map from terrain mesh for neighbor sampling in shaders.

Output: textures/terrain_normals.png (RGB encoded normals)

Usage:

from generate_normal_map import save_normal_map

save_normal_map(
    output_path=project_root / "textures" / "terrain_normals.png",
    resolution=1024,
    blur_iterations=2,
    terrain_name="TerrainPlane"
)

generate_flowmap.py

Generates flowmap for water/snow flow effects.

Output: textures/terrain_flowmap.png

Terrain Export Workflow

1. Model terrain in Blender 5.0

   • Create/sculpt terrain mesh
   • Add modifiers (Subdivision, Displacement, etc.)
   • Ensure terrain has UV mapping

2. Bake heightmap

   • Run generate_heightmap.py script
   • Uses Blender's baking system (like baking a texture)
   • Creates textures/terrain_heightmap.exr
   • Automatically applies all modifiers

3. Export glTF with baked heights

   • Select terrain mesh
   • File → Export → glTF 2.0
   • Save as meshes/terrain.gltf
   • Heights are baked in vertex positions

4. Both files in sync

   • glTF: rendering (vertices with baked heights)
   • EXR: physics (rapier3d heightfield collider)
   • Both from same source = guaranteed match

Resolution Guidelines

• Heightmap (EXR): 512×512, 1000×1000, or 1024×1024

  • Higher = more accurate collision
  • Lower = faster loading
  • Default: 1000×1000
  • Uses Blender's render sampling (no gaps!)

• Normal Map: 1024×1024 or 2048×2048

  • For shader neighbor sampling
  • Higher quality for detailed terrain

Customization

Change parameters by editing the script or calling directly:

from generate_heightmap import bake_heightmap

bake_heightmap(
    terrain_obj=bpy.data.objects["MyTerrain"],
    resolution=1024,
    output_path="custom/path.exr"
)

Output Files

project_root/
├── meshes/
│   └── terrain.gltf        # Mesh with baked heights (manual export)
└── textures/
    ├── terrain.exr         # Heightmap for physics (generated)
    ├── terrain_normals.png # Normal map (generated)
    └── terrain_flowmap.png # Flow map (generated)

Troubleshooting

"Object not found":

• Ensure terrain object exists
• Check object name matches parameter
• Script will auto-detect objects with "terrain" or "plane" in name

"Mesh has no vertices":

• Apply all modifiers before running script
• Check mesh is not empty

EXR export fails:

• Ensure Blender has EXR support enabled
• Check output directory exists and is writable