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

tests/tools/nodes/test_depth_surface_split.py

@@ -75,8 +75,8 @@ def test_split_mapping_and_uniform_scale(size):
     assert counts[:3] == [15] * 3
     assert counts[3] == 18
     set_value("Depth Scale", 0.0)
-    coords, faces = evaluated(obj)
-    assert len(coords) == 18 and np.abs(coords[:, 1]).max() < 1e-6
+    coords, _ = evaluated(obj)
+    assert len(coords) == counts[0] and np.abs(coords[:, 1]).max() < 1e-6
 
 
 def test_midpoint_selects_relative_ray_jump_and_preserves_faces():
@@ -87,16 +87,33 @@ def test_midpoint_selects_relative_ray_jump_and_preserves_faces():
     assert set(np.round(coords[:, 1], 4)) == {2.0, -2.0}
 
 
-@pytest.mark.parametrize("depth_scale", [0.0, 2.0])
-def test_split_topology_uses_depth_before_display_scaling(depth_scale):
+@pytest.mark.parametrize("depth_scale", [0.0, 1.0])
+def test_depth_scale_scales_split_selection(depth_scale):
     obj, set_value = surface(step=4.0)
-    set_value("Depth Split", 0.5)
-    original, original_faces = evaluated(obj)
     set_value("Depth Scale", depth_scale)
+    set_value("Depth Split", 0.0)
+    whole, whole_faces = evaluated(obj)
+    set_value("Depth Split", 0.5)
     coords, faces = evaluated(obj)
-    assert len(coords) == len(original) == 18
-    assert faces == original_faces
-    np.testing.assert_allclose(coords[:, 1], original[:, 1] * depth_scale, atol=1e-6)
+    assert np.isfinite(coords).all()
+    if depth_scale == 0.0:
+        # A flat projection keeps every face, so there is nothing to separate.
+        np.testing.assert_allclose(coords, whole, atol=1e-6)
+        assert faces == whole_faces
+    else:
+        assert len(coords) > len(whole)
+
+
+def test_depth_scale_multiplies_split_strength():
+    obj, set_value = surface(step=4.0)
+    set_value("Depth Scale", 0.5)
+    set_value("Depth Split", 1.0)
+    scaled, scaled_faces = evaluated(obj)
+    set_value("Depth Scale", 1.0)
+    set_value("Depth Split", 0.5)
+    reference, reference_faces = evaluated(obj)
+    assert len(scaled) == len(reference) > 15
+    assert scaled_faces == reference_faces
 
 
 def test_full_wrapper_keeps_closed_shell():
@@ -314,6 +331,7 @@ def test_split_uses_ray_distance_and_ignores_absolute_distance_scale(kind):
     if kind == "plane":
         obj, set_value, _, _, image = create_surface("DEPTH")
         set_value("Subdivide", 1)
+        set_value("Depth Scale", 1)
     else:
         obj, set_value = surface(step=0)
         image = bpy.data.images["Camera"]