render iteration

blender/scripts/generate_heightmap.py

@@ -0,0 +1,135 @@
+import bpy
+from pathlib import Path
+
+
+def bake_heightmap(terrain_obj, resolution=1024, output_path=None):
+    """
+    Bake terrain heightmap using Blender's render/bake system.
+
+    Args:
+        terrain_obj: Terrain mesh object
+        resolution: Texture resolution (square)
+        output_path: Path to save EXR file
+    """
+
+    print(f"Baking heightmap for: {terrain_obj.name}")
+    print(f"Resolution: {resolution}×{resolution}")
+
+    # Ensure object has UV map
+    if not terrain_obj.data.uv_layers:
+        print("Adding UV map...")
+        terrain_obj.data.uv_layers.new(name="UVMap")
+
+    # Create new image for baking
+    bake_image = bpy.data.images.new(
+        name="Heightmap_Bake",
+        width=resolution,
+        height=resolution,
+        alpha=False,
+        float_buffer=True,
+        is_data=True
+    )
+
+    # Setup material for baking
+    if not terrain_obj.data.materials:
+        mat = bpy.data.materials.new(name="Heightmap_Material")
+        terrain_obj.data.materials.append(mat)
+    else:
+        mat = terrain_obj.data.materials[0]
+
+    mat.use_nodes = True
+    nodes = mat.node_tree.nodes
+    nodes.clear()
+
+    # Create nodes for height baking
+    # Geometry node to get position
+    geo_node = nodes.new(type='ShaderNodeNewGeometry')
+
+    # Separate XYZ to get Z (height)
+    separate_node = nodes.new(type='ShaderNodeSeparateXYZ')
+    mat.node_tree.links.new(geo_node.outputs['Position'], separate_node.inputs['Vector'])
+
+    # Emission shader to output height value
+    emission_node = nodes.new(type='ShaderNodeEmission')
+    mat.node_tree.links.new(separate_node.outputs['Z'], emission_node.inputs['Color'])
+
+    # Material output
+    output_node = nodes.new(type='ShaderNodeOutputMaterial')
+    mat.node_tree.links.new(emission_node.outputs['Emission'], output_node.inputs['Surface'])
+
+    # Add image texture node (required for baking target)
+    image_node = nodes.new(type='ShaderNodeTexImage')
+    image_node.image = bake_image
+    image_node.select = True
+    nodes.active = image_node
+
+    # Select object and set mode
+    bpy.context.view_layer.objects.active = terrain_obj
+    terrain_obj.select_set(True)
+
+    # Setup render settings for baking
+    bpy.context.scene.render.engine = 'CYCLES'
+    bpy.context.scene.cycles.samples = 1
+    bpy.context.scene.cycles.bake_type = 'EMIT'
+
+    print("Baking...")
+    bpy.ops.object.bake(type='EMIT', use_clear=True)
+
+    print("Bake complete!")
+
+    # Save as EXR
+    if output_path:
+        bake_image.filepath_raw = str(output_path)
+        bake_image.file_format = 'OPEN_EXR'
+        bake_image.use_half_precision = False
+
+        scene = bpy.context.scene
+        original_color_mode = scene.render.image_settings.color_mode
+        original_color_depth = scene.render.image_settings.color_depth
+
+        scene.render.image_settings.color_mode = 'BW'
+        scene.render.image_settings.color_depth = '32'
+
+        bake_image.save_render(str(output_path), scene=scene)
+
+        scene.render.image_settings.color_mode = original_color_mode
+        scene.render.image_settings.color_depth = original_color_depth
+
+        print(f"Saved to: {output_path}")
+
+    # Cleanup
+    bpy.data.images.remove(bake_image)
+
+    return True
+
+
+if __name__ == "__main__":
+    project_root = Path(bpy.data.filepath).parent.parent
+    output_path = project_root / "textures" / "terrain_heightmap.exr"
+
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+
+    # Find terrain object
+    terrain_obj = bpy.data.objects.get("TerrainPlane")
+
+    if not terrain_obj:
+        print("'TerrainPlane' not found. Searching for terrain mesh...")
+        for obj in bpy.data.objects:
+            if obj.type == 'MESH' and ('terrain' in obj.name.lower() or 'plane' in obj.name.lower()):
+                terrain_obj = obj
+                print(f"Using: {obj.name}")
+                break
+
+    if not terrain_obj:
+        raise ValueError("No terrain object found!")
+
+    bake_heightmap(
+        terrain_obj=terrain_obj,
+        resolution=1000,
+        output_path=output_path
+    )
+
+    print("\n" + "="*60)
+    print("Heightmap baking complete!")
+    print(f"Output: {output_path}")
+    print("="*60)