Refactor depth surface handling and unify depth sampling rules

- Removed the `always_vertex` parameter from `build_surface_camera` to streamline depth sampling for cutouts and ensure consistent behavior across depth plane and panorama.
- Updated depth sampling logic to ensure that all free boundary points, including the original frame of the depth plane, use neighboring face depth instead of their own texture sampling.
- Adjusted the depth mask deletion process to operate on faces rather than points, eliminating the need for additional cleanup of dangling edges.
- Ensured that the cutout rules are consistently applied across all relevant nodes, removing exceptions and simplifying the logic.
- Updated tests to verify the new behavior, ensuring that cutout points follow the depth of adjacent faces and that the original frame maintains its depth sampling.
- Refactored geometry handling in multiple depth-related nodes to improve clarity and maintainability.

tools/nodes/common/depth_surface.py

@@ -1,6 +1,7 @@
 """Face separation and connected thickness for Depth Surface assets."""
 
 from .nodes import evaluate_field, store_float_attribute, store_boolean_attribute, remove_attribute_pattern, sample_field
+from .smoothing import edge_boundary_field
 
 
 CUT_ATTRIBUTE = "_o_anyimage_depth_cut"
@@ -275,21 +276,24 @@ def split_depth_surface(group, geometry, face_camera, strength, reference_depth,
     return choose.outputs["Output"], face_camera, cut
 
 
-def build_surface_camera(group, original, separated, cut_vertex, strength, *, always_vertex=None):
-    """Change cut depth along the original ray, preserving every other vertex."""
-    enabled = group.nodes.new("GeometryNodeSwitch")
+def build_surface_camera(group, original, separated, cut_vertex, strength):
+    """Take cut depth from the adjacent face sample along each unchanged ray.
+
+    Depth Split edges and every open boundary left by Depth Mask deletion share
+    one replacement, so each cut edge sits on the surface it belongs to.
+    """
+    nodes, links = group.nodes, group.links
+    cut_boundary = evaluate_field(group, edge_boundary_field(nodes, links), "BOOLEAN", "POINT")
+    enabled = nodes.new("GeometryNodeSwitch")
     enabled.input_type = "BOOLEAN"
-    group.links.new(_math(group, "GREATER_THAN", strength, 0.0), enabled.inputs["Switch"])
+    links.new(_math(group, "GREATER_THAN", strength, 0.0), enabled.inputs["Switch"])
     enabled.inputs["False"].default_value = False
-    group.links.new(cut_vertex, enabled.inputs["True"])
-    if always_vertex is not None:
-        combined = group.nodes.new("FunctionNodeBooleanMath")
-        combined.operation = "OR"
-        group.links.new(enabled.outputs["Output"], combined.inputs[0])
-        group.links.new(always_vertex, combined.inputs[1])
-        enabled = combined.outputs["Boolean"]
-    else:
-        enabled = enabled.outputs["Output"]
+    links.new(cut_vertex, enabled.inputs["True"])
+    combined = nodes.new("FunctionNodeBooleanMath")
+    combined.operation = "OR"
+    links.new(enabled.outputs["Output"], combined.inputs[0])
+    links.new(cut_boundary, combined.inputs[1])
+    enabled = combined.outputs["Boolean"]
     original_axes = group.nodes.new("ShaderNodeSeparateXYZ")
     separated_axes = group.nodes.new("ShaderNodeSeparateXYZ")
     group.links.new(original, original_axes.inputs[0])