Optimize Cutout Geometry Nodes

- Refactor Depth Cutout to reuse the projected outline field, reducing redundant boundary calculations and improving performance.
- Derive the center field from shared low-frequency fields, eliminating an unnecessary blur operation.
- Implement triangle-only strip cleanup for Depth Cutout, as the input is confirmed to be triangulated.
- Short-circuit zero-thickness branches in both Cutout and Depth Cutout to avoid unnecessary geometry generation.
- Standardize internal attribute naming with a new `_o_` prefix and implement wildcard cleanup for temporary attributes.
- Update relevant tests to ensure functionality remains consistent and validate changes against existing behavior.

tools/nodes/common/boundary_smoothing.py

@@ -77,10 +77,11 @@ def reconstruct_camera_depth(group, camera, depth, smoothed):
     return choose.outputs[0]
 
 
-def cut_boundary_influence(group, split_boundary, protected=False, *, outline_scale=0.1):
+def cut_boundary_influence(group, split_boundary, protected=False, *, outline_scale=0.1, boundary=None):
     """Give split edges full influence and outline edges a configured share."""
     nodes, links = group.nodes, group.links
-    boundary = evaluate_field(group, edge_boundary_field(nodes, links), "FLOAT", "POINT")
+    if boundary is None:
+        boundary = evaluate_field(group, edge_boundary_field(nodes, links), "FLOAT", "POINT")
     split = _math(group, "MULTIPLY", boundary, split_boundary)
     outline = _math(group, "MAXIMUM", _math(group, "SUBTRACT", boundary, split), 0)
     split_influence = boundary_influence(group, protected, boundary=split)
@@ -90,9 +91,11 @@ def cut_boundary_influence(group, split_boundary, protected=False, *, outline_sc
     return _math(group, "MAXIMUM", split_influence, outline_influence)
 
 
-def smooth_cut_boundary(group, geometry, split_boundary=False, *, protected=False, outline_scale=0.1):
+def smooth_cut_boundary(group, geometry, split_boundary=False, *, protected=False, outline_scale=0.1, boundary=None):
     """Blend O Smooth through split and outline masks with configurable weights."""
-    influence = cut_boundary_influence(group, split_boundary, protected, outline_scale=outline_scale)
+    influence = cut_boundary_influence(
+        group, split_boundary, protected, outline_scale=outline_scale, boundary=boundary,
+    )
     # The support band depends on topology, which stays unchanged in the loop.
     return expand_smooth(
         group, geometry, iterations_name="Boundary Smooth", weight_name="Smooth Weight",