Fix incorrect ECEF->LLH transformation in CesiumCartographicPolygon.

Author: kring

CHANGES.md

@@ -5,6 +5,7 @@
 ##### Fixes :wrench:
 
 - Fixed a bug that caused a `NullReferenceException` when attempting to get or set the `longitudeLatitudeHeight` property on a disabled `CesiumGlobeAnchor`.
+- Fixed a bug introduced in v1.11.0 that caused `CesiumCartographicPolygon` positions to be interpreted incorrectly, making polygon clipping unusable.
 
 ### v1.11.0 - 2024-07-01
 

Runtime/CesiumCartographicPolygon.cs

@@ -138,7 +138,7 @@ internal List<double2> GetCartographicPoints(Matrix4x4 worldToTileset)
                 float3 worldPosition = knot.Transform(localToWorld).Position;
                 float3 unityPosition = worldToTileset.MultiplyPoint3x4(worldPosition);
                 double3 ecefPosition = georeference.TransformUnityPositionToEarthCenteredEarthFixed(unityPosition);
-                double3 cartographicPosition = georeference.ellipsoid.LongitudeLatitudeHeightToCenteredFixed(ecefPosition);
+                double3 cartographicPosition = georeference.ellipsoid.CenteredFixedToLongitudeLatitudeHeight(ecefPosition);
 
                 cartographicPoints.Add(cartographicPosition.xy);
             }

Tests/CesiumTests.asmdef

@@ -5,7 +5,8 @@
         "UnityEngine.TestRunner",
         "UnityEditor.TestRunner",
         "CesiumRuntime",
-        "Unity.Mathematics"
+        "Unity.Mathematics",
+        "Unity.Splines"
     ],
     "includePlatforms": [],
     "excludePlatforms": [],
@@ -18,6 +19,12 @@
     "defineConstraints": [
         "UNITY_INCLUDE_TESTS"
     ],
-    "versionDefines": [],
+    "versionDefines": [
+        {
+            "name": "com.unity.splines",
+            "expression": "1.0.0",
+            "define": "SUPPORTS_SPLINES"
+        }
+    ],
     "noEngineReferences": false
 }

Tests/TestCesiumCartographicPolygon.cs

@@ -0,0 +1,62 @@
+using CesiumForUnity;
+using NUnit.Framework;
+using System.Collections.Generic;
+using Unity.Mathematics;
+using UnityEngine;
+
+#if SUPPORTS_SPLINES
+using UnityEngine.Splines;
+#endif
+
+public class TestCesiumCartographicPolygon
+{
+#if SUPPORTS_SPLINES
+    [Test]
+    public void GetCartographicPoints()
+    {
+        GameObject go = new GameObject("Game Object");
+
+        CesiumGeoreference georeference = go.AddComponent<CesiumGeoreference>();
+        georeference.SetOriginLongitudeLatitudeHeight(12.0, 23.0, 456.0);
+
+        CesiumCartographicPolygon polygonComponent = go.AddComponent<CesiumCartographicPolygon>();
+        SplineContainer splineContainer = go.GetComponent<SplineContainer>();
+
+        // Remove existing spline(s).
+        IReadOnlyList<Spline> splines = splineContainer.Splines;
+        for (int i = splines.Count - 1; i >= 0; i--)
+        {
+            splineContainer.RemoveSpline(splines[i]);
+        }
+
+        // Add a new spline.
+        Spline defaultSpline = new Spline();
+
+        BezierKnot[] knots = new BezierKnot[] {
+            new BezierKnot(new float3(-100.0f, 0f, -100.0f)),
+            new BezierKnot(new float3(100.0f, 0f, -100.0f)),
+            new BezierKnot(new float3(100.0f, 0f, 100.0f)),
+            new BezierKnot(new float3(-100.0f, 0f, 100.0f)),
+        };
+
+        defaultSpline.Knots = knots;
+        defaultSpline.Closed = true;
+        defaultSpline.SetTangentMode(TangentMode.Linear);
+
+        splineContainer.AddSpline(defaultSpline);
+
+        List<double2> cartographicPoints = polygonComponent.GetCartographicPoints(Matrix4x4.identity);
+        Assert.AreEqual(cartographicPoints.Count, 4);
+
+        // All points are near the georeference origin
+        Assert.AreEqual(cartographicPoints[0].x, 12.0, 0.01);
+        Assert.AreEqual(cartographicPoints[0].y, 23.0, 0.01);
+        Assert.AreEqual(cartographicPoints[1].x, 12.0, 0.01);
+        Assert.AreEqual(cartographicPoints[1].y, 23.0, 0.01);
+        Assert.AreEqual(cartographicPoints[2].x, 12.0, 0.01);
+        Assert.AreEqual(cartographicPoints[2].y, 23.0, 0.01);
+        Assert.AreEqual(cartographicPoints[3].x, 12.0, 0.01);
+        Assert.AreEqual(cartographicPoints[3].y, 23.0, 0.01);
+    }
+#endif
+}