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.

tests/tools/nodes/test_cutout_symmetry.py

@@ -113,6 +113,7 @@ def test_symmetry_interface_and_cutout_defaults(symmetry):
         "Scale",
         "Fill Sides",
         "Fill Smooth",
+        "Seam Smooth",
     ]
     assert tuple(mirror_inputs[1].default_value) == (0, 0, 1)
     assert mirror_inputs[3].default_value == 1
@@ -219,7 +220,7 @@ def test_disabled_fill_keeps_the_welded_seam(symmetry):
     assert not any(plane[edge[0]] and plane[edge[1]] for edge in open_edges)
 
 
-def test_fill_smooth_only_relaxes_the_seam(symmetry):
+def test_fill_smooth_relaxes_the_junction_band(symmetry):
     obj, _cutout, _mirror, _cutout_setter, mirror_setter = symmetry
     mirror_setter("Fill Sides", True)
     mirror_setter("Fill Smooth", 0)
@@ -232,17 +233,67 @@ def test_fill_smooth_only_relaxes_the_seam(symmetry):
         plane = np.abs(points[:, 0]) <= tolerance
         assert plane.any()
         assert not any(all(plane[index] for index in face) for face in faces)
-    plain_interior = _front_vertices(
-        plain_points, plain_faces, plain_marker, lambda point: point[0] > tolerance
+    assert smooth_faces == plain_faces
+    axis = np.abs(plain_points[:, 0]) <= tolerance
+    moved = np.linalg.norm(smooth_points - plain_points, axis=1)
+    # 衔接带同时覆盖对称轴上的点与外侧轮廓。
+    assert moved[axis].max() > 1e-4
+    plain_rim = _positions(_front_rim(plain_points, plain_faces, plain_marker, tolerance))
+    smooth_rim = _positions(_front_rim(smooth_points, smooth_faces, smooth_marker, tolerance))
+    assert plain_rim != smooth_rim
+
+
+def test_fill_smooth_band_reaches_beyond_two_rings():
+    """Fill Smooth 平滑的是衔接带，覆盖范围比原先的两圈更宽。"""
+    from tools.nodes.common.depth_surface import _math
+    from tools.nodes.groups.image_cutout_symmetry import FILL_SMOOTH_RINGS, _falloff
+
+    bpy.ops.wm.read_factory_settings(use_empty=True)
+    size, rows = FILL_SMOOTH_RINGS + 4, 3
+    points = [(x, 0.0, y) for y in range(rows) for x in range(size)]
+    faces = [
+        (
+            y * size + x,
+            y * size + x + 1,
+            (y + 1) * size + x + 1,
+            (y + 1) * size + x,
+        )
+        for y in range(rows - 1)
+        for x in range(size - 1)
+    ]
+    mesh = bpy.data.meshes.new("Fill band")
+    mesh.from_pydata(points, [], faces)
+    obj = bpy.data.objects.new("Fill band", mesh)
+    bpy.context.collection.objects.link(obj)
+    group = bpy.data.node_groups.new("Fill band", "GeometryNodeTree")
+    for direction in ("INPUT", "OUTPUT"):
+        group.interface.new_socket(
+            name="Geometry", in_out=direction, socket_type="NodeSocketGeometry"
+        )
+    source = group.nodes.new("NodeGroupInput")
+    position = group.nodes.new("GeometryNodeInputPosition")
+    axes = group.nodes.new("ShaderNodeSeparateXYZ")
+    group.links.new(position.outputs[0], axes.inputs[0])
+    outline = _math(group, "COMPARE", axes.outputs["X"], 0)
+    store = group.nodes.new("GeometryNodeStoreNamedAttribute")
+    store.data_type, store.domain = "FLOAT", "POINT"
+    store.inputs["Name"].default_value = "fill_band"
+    group.links.new(source.outputs["Geometry"], store.inputs["Geometry"])
+    group.links.new(_falloff(group, outline, FILL_SMOOTH_RINGS), store.inputs["Value"])
+    group.links.new(
+        store.outputs["Geometry"], group.nodes.new("NodeGroupOutput").inputs["Geometry"]
     )
-    smooth_interior = _front_vertices(
-        smooth_points, smooth_faces, smooth_marker, lambda point: point[0] > tolerance
-    )
-    assert _positions(plain_interior) == _positions(smooth_interior)
-    plain_rim = _front_rim(plain_points, plain_faces, plain_marker, tolerance)
-    smooth_rim = _front_rim(smooth_points, smooth_faces, smooth_marker, tolerance)
-    assert plain_rim.shape == smooth_rim.shape
-    assert not np.allclose(np.sort(plain_rim[:, 1:], axis=0), np.sort(smooth_rim[:, 1:], axis=0))
+    obj.modifiers.new("Fill band", "NODES").node_group = group
+    result = obj.evaluated_get(bpy.context.evaluated_depsgraph_get())
+    data = result.to_mesh()
+    try:
+        band = np.array(
+            [item.value for item in data.attributes["fill_band"].data]
+        ).reshape(rows, size)
+    finally:
+        result.to_mesh_clear()
+    assert (band[:, 3] > 0).all()
+    assert (band[:, FILL_SMOOTH_RINGS + 1] == 0).all()
 
 
 def test_object_normal_attributes_follow_final_orientation(symmetry):