feat(node_assets): add image plane geometry nodes and validation scripts

- Implemented `image_plane.py` to build the Image Plane Geometry Nodes group with customizable parameters for geometry, subdivide, and thickness.
- Created `image_plane_validation.py` to validate the functionality of the image plane, ensuring correct geometry generation and material assignment.
- Developed `material_layers.py` to construct shader node groups for image materials, including depth and normal handling.
- Authored `plane_layouts.py` to define node arrangements for image geometry assets.
- Introduced `shadeless.py` to create a shadeless shader node group that displays color without scene lighting while preserving shadows and reflections.

tests/test_balloon_profiles.py

@@ -0,0 +1,86 @@
+
+
+import sys
+from pathlib import Path
+from unittest.mock import patch
+import numpy as np
+
+SOURCE_ROOT = Path(__file__).parents[1] / "src"
+
+sys.path.insert(0, str(SOURCE_ROOT))
+
+
+from anyimage.operators.cutout_tool import geometry as cutout_geometry
+from anyimage.operators.cutout_tool.geometry import poisson_balloon_profile
+
+
+def test_poisson_balloon_profile_is_zero_on_boundary_and_positive_inside():
+    points = np.asarray(
+        ((0, 0), (2, 0), (2, 2), (0, 2), (1, 1)),
+        dtype=float,
+    )
+    faces = ((0, 1, 4), (1, 2, 4), (2, 3, 4), (3, 0, 4))
+    boundary = np.asarray((True, True, True, True, False))
+
+    profile = poisson_balloon_profile(points, faces, boundary)
+
+    assert np.all(profile[:4] == 0.0)
+    assert profile[4] > 0.0
+
+
+def test_poisson_balloon_profile_scales_in_world_units():
+    points = np.asarray(
+        ((0, 0), (2, 0), (2, 2), (0, 2), (1, 1)),
+        dtype=float,
+    )
+    faces = ((0, 1, 4), (1, 2, 4), (2, 3, 4), (3, 0, 4))
+    boundary = np.asarray((True, True, True, True, False))
+
+    original = poisson_balloon_profile(points, faces, boundary)
+    scaled = poisson_balloon_profile(points * 2.0, faces, boundary)
+
+    assert np.isclose(scaled[4], original[4] * 2.0, atol=1e-6)
+
+
+def test_poisson_balloon_profile_makes_wide_selections_thicker():
+    faces = ((0, 1, 4), (1, 2, 4), (2, 3, 4), (3, 0, 4))
+    boundary = np.asarray((True, True, True, True, False))
+    wide = np.asarray(
+        ((0, 0), (4, 0), (4, 2), (0, 2), (2, 1)),
+        dtype=float,
+    )
+    narrow = np.asarray(
+        ((0, 0), (4, 0), (4, 0.6), (0, 0.6), (2, 0.3)),
+        dtype=float,
+    )
+
+    wide_profile = poisson_balloon_profile(wide, faces, boundary)
+    narrow_profile = poisson_balloon_profile(narrow, faces, boundary)
+
+    assert wide_profile[4] > narrow_profile[4]
+
+
+def test_teddy_balloon_profile_uses_chordal_axis_radius():
+    points = np.asarray(
+        ((0, 0), (4, 0), (4, 2), (0, 2), (2, 1)),
+        dtype=float,
+    )
+    faces = ((0, 1, 4), (1, 2, 4), (2, 3, 4), (3, 0, 4))
+    boundary = np.asarray((True, True, True, True, False))
+    nodes = np.asarray(((1, 1), (3, 1)), dtype=float)
+
+    with patch.object(
+        cutout_geometry,
+        "chordal_axis",
+        return_value=(nodes, [(0, 1)], np.asarray((1.0, 1.0))),
+    ):
+        profile = cutout_geometry.teddy_balloon_heights(
+            points,
+            faces,
+            points[:4],
+            boundary,
+            0.45,
+        )
+
+    assert np.all(profile[:4] == 0.0)
+    assert np.isclose(profile[4], 0.45, atol=1e-6)