tile-export-pipeline

Tile Export Pipeline — Blender to Game-Ready FBX

Overview

Export photogrammetry terrain tiles from Blender to FBX for game engines (Unreal, Unity, Godot). Enforces strict rules for transforms, scale, and axis conventions to ensure tiles load correctly.

Golden Rules

1. NEVER alter object-level transforms. Location, Rotation, and Scale must stay at identity (0,0,0 / 0,0,0 / 1,1,1). All geometry changes happen in EDIT MODE only. If you need to move/rotate geometry, do it on the mesh data, not the object transform.
2. FBX_SCALE_NONE — never use FBX_SCALE_ALL or any other scale option. Photogrammetry tiles are already in real-world meters.
3. Axis: forward='-Z', up='Y' — standard Blender-to-game-engine convention.
4. Tile naming: Tile_X-Y where X-Y are grid coordinates.

Export Settings

bpy.ops.export_scene.fbx(
    filepath="/path/to/output/Tile_X-Y.fbx",
    use_selection=True,
    apply_scale_options='FBX_SCALE_NONE',
    axis_forward='-Z',
    axis_up='Y',
    use_mesh_modifiers=True,
    mesh_smooth_type='OFF',
    use_tspace=True,
    embed_textures=False,
    path_mode='COPY'
)

Pre-Export Checklist

Before exporting any tile, verify:

1. Identity transforms — Object Location=(0,0,0), Rotation=(0,0,0), Scale=(1,1,1)
2. Clean geometry — No loose vertices, non-manifold edges removed if needed
3. UVs present — Top-down orthographic projection applied
4. Correct selection — Only the target tile object is selected
5. Naming — Object named Tile_X-Y matching grid position

Batch Export Pattern

For each tile object in the scene:

import bpy

for obj in bpy.data.objects:
    if not obj.name.startswith("Tile_"):
        continue

    # Deselect all, select this tile
    bpy.ops.object.select_all(action='DESELECT')
    obj.select_set(True)
    bpy.context.view_layer.objects.active = obj

    # Verify identity transform
    assert obj.location.length < 0.001, f"{obj.name} has non-zero location!"
    assert abs(obj.scale.x - 1.0) < 0.001, f"{obj.name} has non-unit scale!"

    # Export
    filepath = f"/path/to/output/{obj.name}.fbx"
    bpy.ops.export_scene.fbx(
        filepath=filepath,
        use_selection=True,
        apply_scale_options='FBX_SCALE_NONE',
        axis_forward='-Z',
        axis_up='Y',
        use_mesh_modifiers=True,
        mesh_smooth_type='OFF',
        use_tspace=True,
        embed_textures=False
    )

Common Issues

• Scale looks wrong in engine: Verify FBX_SCALE_NONE — any other option will bake Blender's scale factor.
• Tile rotated/offset in engine: Object transform was not identity. Check Location/Rotation/Scale in Blender.
• UV seams visible: Re-project UVs with orthographic top-down. Seam placement matters less for terrain.