Fix Metashape tangential distortion import

nerfstudio/process_data/metashape_utils.py

@@ -110,8 +110,9 @@ def metashape_to_json(
             s["k2"] = _find_param(calib, "k2")
             s["k3"] = _find_param(calib, "k3")
             s["k4"] = _find_param(calib, "k4")
-            s["p1"] = _find_param(calib, "p1")
-            s["p2"] = _find_param(calib, "p2")
+            # Metashape and OpenCV reverse the p1 and p2 names for the same tangential terms.
+            s["p1"] = _find_param(calib, "p2")
+            s["p2"] = _find_param(calib, "p1")
 
         sensor_dict[sensor.get("id")] = s
 

tests/process_data/test_metashape_utils.py

@@ -0,0 +1,54 @@
+# Copyright 2022 the Regents of the University of California, Nerfstudio Team and contributors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for importing Metashape camera data."""
+
+import json
+from pathlib import Path
+
+from nerfstudio.process_data.metashape_utils import metashape_to_json
+
+
+def test_metashape_tangential_distortion_conversion(tmp_path: Path):
+    xml_path = tmp_path / "cameras.xml"
+    xml_path.write_text(
+        """<?xml version="1.0" encoding="UTF-8"?>
+<document>
+  <chunk>
+    <sensors>
+      <sensor id="0" type="frame">
+        <resolution width="1000" height="800"/>
+        <calibration>
+          <f>500</f>
+          <p1>0.001</p1>
+          <p2>-0.002</p2>
+        </calibration>
+      </sensor>
+    </sensors>
+    <cameras>
+      <camera id="0" sensor_id="0" label="image">
+        <transform>1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1</transform>
+      </camera>
+    </cameras>
+  </chunk>
+</document>
+""",
+        encoding="utf-8",
+    )
+
+    metashape_to_json({"image": Path("images/image.jpg")}, xml_path, tmp_path)
+
+    transforms = json.loads((tmp_path / "transforms.json").read_text(encoding="utf-8"))
+    assert transforms["frames"][0]["p1"] == -0.002
+    assert transforms["frames"][0]["p2"] == 0.001