refactor: incorporate Depth Scale into Depth Split criteria for consistent geometry handling

tests/tools/nodes/test_cutout_boundary.py

@@ -20,6 +20,18 @@ def profile_values(obj):
         result.to_mesh_clear()
 
 
+def vertex_uv(obj):
+    result = obj.evaluated_get(bpy.context.evaluated_depsgraph_get())
+    mesh = result.to_mesh()
+    try:
+        uv = np.zeros((len(mesh.vertices), 2))
+        for loop in mesh.loops:
+            uv[loop.vertex_index] = mesh.uv_layers["UVMap"].data[loop.index].uv
+        return uv
+    finally:
+        result.to_mesh_clear()
+
+
 def test_boundary_triangle_cleanup_is_one_pass():
     obj, _ = surface(resolution=2)
     group = obj.modifiers[0].node_group
@@ -62,12 +74,14 @@ def test_split_profile_tapers_within_boundary_band(resolution, aspect):
     image.update()
     obj.data.attributes.new("o_balloon", "FLOAT", "POINT").data.foreach_set(
         "value", np.full(len(obj.data.vertices), .3, dtype=np.float32))
-    set_value("Depth Scale", 0)
+    set_value("Depth Scale", 1)
     np.testing.assert_allclose(profile_values(obj), .3)
     set_value("Depth Split", .1)
     points, faces = evaluated(obj)
     boundary = boundary_neighbors(faces)
-    cut = [i for i in boundary if 0 < points[i,2] < 1 and .5*aspect < points[i,0] < 1.5*aspect]
+    uv = vertex_uv(obj)
+    # The depth step sits at u=0.5, so that column is the split line.
+    cut = [i for i in boundary if abs(uv[i,0] - .5) < 1e-4 and 1e-4 < uv[i,1] < 1 - 1e-4]
     assert cut
     band = edge_band(faces, cut)
     outside = [i for i in range(len(points)) if i not in band]