Refactor geometry generation to standardize Blender object coordinates

- Unified the canonical local frame for generated geometries (Plane, Depth Plane, Relief Plane, Cutout, Depth Cutout) to align with Blender's object coordinate system, setting X as horizontal, Z as up, and +Y as depth.
- Removed the `Depth Axis` parameter from `O Image Cutout` and `O Image Depth Cutout`, simplifying the geometry generation process.
- Updated the depth direction defaults to use +Y instead of -Z for `O Image Relief Plane` and Depth Symmetry.
- Adjusted the geometry nodes to ensure thickness, projection, and shell displacements operate along the Y-axis.
- Implemented new capabilities for handling object space normals to align with the new canonical frame.
- Enhanced the Depth Symmetry functionality to mirror across the canonical Y-axis and perform a final rotation to maintain the correct orientation.
- Added tests to validate the new coordinate system and ensure compatibility with existing assets.

tools/nodes/common/direction.py

@@ -0,0 +1,33 @@
+"""Build nodes that decode legacy Direction parameters into canonical space."""
+
+
+def legacy_direction_to_canonical(group, legacy):
+    nodes = group.nodes
+    links = group.links
+    axes = nodes.new("ShaderNodeSeparateXYZ")
+    links.new(legacy, axes.inputs[0])
+    negative_x = nodes.new("ShaderNodeMath")
+    negative_x.operation = "MULTIPLY"
+    negative_x.inputs[1].default_value = -1.0
+    links.new(axes.outputs["X"], negative_x.inputs[0])
+    negative_y = nodes.new("ShaderNodeMath")
+    negative_y.operation = "MULTIPLY"
+    negative_y.inputs[1].default_value = -1.0
+    links.new(axes.outputs["Y"], negative_y.inputs[0])
+    direction = nodes.new("ShaderNodeCombineXYZ")
+    links.new(negative_x.outputs[0], direction.inputs["X"])
+    links.new(axes.outputs["Z"], direction.inputs["Y"])
+    links.new(negative_y.outputs[0], direction.inputs["Z"])
+    return direction.outputs["Vector"]
+
+
+def symmetry_legacy_direction_to_canonical(group, legacy):
+    nodes = group.nodes
+    links = group.links
+    axes = nodes.new("ShaderNodeSeparateXYZ")
+    links.new(legacy, axes.inputs[0])
+    direction = nodes.new("ShaderNodeCombineXYZ")
+    links.new(axes.outputs["X"], direction.inputs["X"])
+    links.new(axes.outputs["Z"], direction.inputs["Y"])
+    links.new(axes.outputs["Y"], direction.inputs["Z"])
+    return direction.outputs["Vector"]