Fixed visual issue when selecting and moving a face that was grouped in the UV window

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - [PBLD-240] Fixed a bug where buttons for "Create Cube" and "Create PolyShape" appeared incorrectly on Light theme.
 - [PBLD-258] Fixed an bug where clicking a highlighted edge might select a hidden edge instead.
 - [PBLD-262] Fixed a bug in the deep cycling of face selection where faces from hidden meshes would get prioritized
+- [PBLD-276] Fixed a bug where dragging a single face from a connected texture group in the UV Editor caused visual distortion during the drag operation
 
 ## [6.0.7] - 2025-08-28
 

Editor/EditorCore/UVEditor.cs

@@ -92,14 +92,11 @@ static Color DRAG_BOX_COLOR
         static readonly Color SELECTED_COLOR_MANUAL = new Color(1f, .68f, 0f, .39f);
         static readonly Color SELECTED_COLOR_AUTO = new Color(0f, .785f, 1f, .39f);
 
-#if UNITY_STANDALONE_OSX
-        public bool ControlKey { get { return Event.current.modifiers == EventModifiers.Command; } }
-    #else
         public bool ControlKey
         {
-            get { return Event.current.modifiers == EventModifiers.Control; }
+            get { return EditorGUI.actionKey; }
         }
-#endif
+
         public bool ShiftKey
         {
             get { return Event.current.modifiers == EventModifiers.Shift; }
@@ -547,13 +544,17 @@ internal void OnBeginUVModification()
             GUI.FocusControl(string.Empty);
             bool update = false;
 
+            Vector2 originalHandlePosition = handlePosition;
+
             // Make sure all TextureGroups are auto-selected
             for (int i = 0; i < selection.Length; i++)
             {
                 if (selection[i].selectedFaceCount > 0)
                 {
                     int fc = selection[i].selectedFaceCount;
-                    selection[i].SetSelectedFaces(SelectTextureGroups(selection[i], selection[i].selectedFacesInternal));
+                    selection[i].SetSelectedFaces(
+                        SelectTextureGroups(selection[i], selection[i].selectedFacesInternal)
+                    );
 
                     // kinda lame... this will cause setSelectedUVsWithSceneView to be called again.
                     if (fc != selection[i].selectedFaceCount)
@@ -567,9 +568,8 @@ internal void OnBeginUVModification()
             if (update)
             {
                 // UpdateSelection clears handlePosition
-                Vector2 storedHandlePosition = handlePosition;
                 ProBuilderEditor.Refresh();
-                SetHandlePosition(storedHandlePosition, true);
+                SetHandlePosition(originalHandlePosition, true);
             }
 
             CopySelectionUVs(out uv_origins);

Tests/Editor/Editor/UVEditorTest.cs

@@ -9,7 +9,8 @@
 using UnityEngine.ProBuilder.Shapes;
 using EditorUtility = UnityEditor.ProBuilder.EditorUtility;
 
-public class UVEditorWindow
+[TestFixture]
+public class UVEditorTests
 {
     ProBuilderMesh m_cube;
 
@@ -18,7 +19,7 @@ public void Setup()
     {
         m_cube = ShapeFactory.Instantiate<Cube>();
         EditorUtility.InitObject(m_cube);
-	// Unsure UV bounds origin is not at (0,0) lower left
+	    // Unsure UV bounds origin is not at (0,0) lower left
         foreach (var face in m_cube.facesInternal)
             face.uv = new AutoUnwrapSettings(face.uv) { anchor = AutoUnwrapSettings.Anchor.UpperLeft, offset = new Vector2(-0.5f, -0.5f) };
         m_cube.RefreshUV(m_cube.faces);
@@ -31,8 +32,29 @@ public void Setup()
     [TearDown]
     public void Cleanup()
     {
+        // Close the UV Editor window first
+        if (UVEditor.instance != null)
+        {
+            UVEditor.instance.Close();
+        }
+
+        // Clear ProBuilder selections
+        MeshSelection.ClearElementSelection();
+        Selection.activeGameObject = null;
+
+        // Reset tool context
         ToolManager.SetActiveContext<GameObjectToolContext>();
-        UObject.DestroyImmediate(m_cube.gameObject);
+
+        // Destroy the cube
+        if (m_cube != null && m_cube.gameObject != null)
+        {
+            UObject.DestroyImmediate(m_cube.gameObject);
+        }
+
+        m_cube = null;
+
+        // Clear undo to prevent resurrection
+        Undo.ClearAll();
     }
 
     [Test]
@@ -103,4 +125,166 @@ public void Manual_PlanarProjection()
         minimalUV = UVEditor.instance.UVSelectionMinimalUV();
         Assert.That(minimalUV, Is.EqualTo(UVEditor.LowerLeft));
     }
+
+    /// <summary>
+    /// Test that moving a single unconnected face doesn't cause distortion
+    /// </summary>
+    [Test]
+    public void MoveSingleFace_PreservesRelativePositions()
+    {
+        // Setup: One face in manual UV mode, NOT in a texture group
+        var face0 = m_cube.facesInternal[0];
+
+        face0.manualUV = false;
+        face0.textureGroup = -1; // No texture group (isolated face)
+
+        m_cube.ToMesh();
+        m_cube.Refresh();
+
+        // Select the face
+        MeshSelection.SetSelection(m_cube.gameObject);
+        m_cube.SetSelectedFaces(new Face[] { face0 });
+        MeshSelection.OnObjectSelectionChanged();
+
+        // Capture initial UV positions
+        var face0InitialUVs = UnityEngine.ProBuilder.ArrayUtility.ValuesWithIndexes(
+            m_cube.texturesInternal, face0.distinctIndexesInternal);
+
+        // Calculate initial relative offsets within the face
+        Vector2[] face0InitialOffsets = new Vector2[face0InitialUVs.Length];
+        for (int i = 0; i < face0InitialUVs.Length; i++)
+            face0InitialOffsets[i] = face0InitialUVs[i] - face0InitialUVs[0];
+
+        // Simulate a move operation
+        Vector2 moveDelta = new Vector2(0.1f, 0.2f);
+        UVEditor.instance.SceneMoveTool(moveDelta);
+
+        // Get final UV positions
+        var face0FinalUVs = UnityEngine.ProBuilder.ArrayUtility.ValuesWithIndexes(
+            m_cube.texturesInternal, face0.distinctIndexesInternal);
+
+        // TEST 1: Verify each vertex moved by the delta
+        for (int i = 0; i < face0InitialUVs.Length; i++)
+        {
+            Assert.That(face0FinalUVs[i].x, Is.EqualTo(face0InitialUVs[i].x + moveDelta.x).Within(0.0001f),
+                $"Vertex {i} X should move by delta");
+            Assert.That(face0FinalUVs[i].y, Is.EqualTo(face0InitialUVs[i].y + moveDelta.y).Within(0.0001f),
+                $"Vertex {i} Y should move by delta");
+        }
+
+        // TEST 2: Verify relative offsets within the face are preserved (no distortion)
+        for (int i = 0; i < face0FinalUVs.Length; i++)
+        {
+            Vector2 finalOffset = face0FinalUVs[i] - face0FinalUVs[0];
+            Assert.That(finalOffset.x, Is.EqualTo(face0InitialOffsets[i].x).Within(0.0001f),
+                $"Vertex {i} relative X offset changed - face was distorted!");
+            Assert.That(finalOffset.y, Is.EqualTo(face0InitialOffsets[i].y).Within(0.0001f),
+                $"Vertex {i} relative Y offset changed - face was distorted!");
+        }
+
+        // Cleanup
+        UVEditor.instance.OnFinishUVModification();
+    }
+
+    [Test]
+    public void MoveConnectedFaces_PreservesRelativePositions()
+    {
+        // Setup: Two faces in the same texture group (Auto UV mode)
+        var face0 = m_cube.facesInternal[0];
+        var face1 = m_cube.facesInternal[1];
+
+        face0.manualUV = false;
+        face1.manualUV = false;
+        face0.textureGroup = 1;
+        face1.textureGroup = 1;
+
+        m_cube.ToMesh();
+        m_cube.Refresh();
+
+        // Select ONLY face0
+        MeshSelection.SetSelection(m_cube.gameObject);
+        m_cube.SetSelectedFaces(new Face[] { face0 });
+        MeshSelection.OnObjectSelectionChanged();
+
+        // Capture initial UV positions of BOTH faces
+        var face0InitialUVs = UnityEngine.ProBuilder.ArrayUtility.ValuesWithIndexes(
+            m_cube.texturesInternal, face0.distinctIndexesInternal);
+        var face1InitialUVs = UnityEngine.ProBuilder.ArrayUtility.ValuesWithIndexes(
+            m_cube.texturesInternal, face1.distinctIndexesInternal);
+
+        // Calculate initial relative offsets within each face
+        Vector2[] face0InitialOffsets = new Vector2[face0InitialUVs.Length];
+        for (int i = 0; i < face0InitialUVs.Length; i++)
+            face0InitialOffsets[i] = face0InitialUVs[i] - face0InitialUVs[0];
+
+        Vector2[] face1InitialOffsets = new Vector2[face1InitialUVs.Length];
+        for (int i = 0; i < face1InitialUVs.Length; i++)
+            face1InitialOffsets[i] = face1InitialUVs[i] - face1InitialUVs[0];
+
+        // Calculate initial distance between the two faces
+        Vector2 face0InitialCenter = Bounds2D.Center(face0InitialUVs);
+        Vector2 face1InitialCenter = Bounds2D.Center(face1InitialUVs);
+        Vector2 initialCenterDistance = face1InitialCenter - face0InitialCenter;
+
+        // Simulate a move operation
+        Vector2 moveDelta = new Vector2(0.1f, 0.2f);
+        UVEditor.instance.SceneMoveTool(moveDelta);
+
+        // Get final UV positions
+        var face0FinalUVs = UnityEngine.ProBuilder.ArrayUtility.ValuesWithIndexes(
+            m_cube.texturesInternal, face0.distinctIndexesInternal);
+        var face1FinalUVs = UnityEngine.ProBuilder.ArrayUtility.ValuesWithIndexes(
+            m_cube.texturesInternal, face1.distinctIndexesInternal);
+
+        // TEST 1: Verify each vertex in face0 moved by the delta
+        for (int i = 0; i < face0InitialUVs.Length; i++)
+        {
+            Assert.That(face0FinalUVs[i].x, Is.EqualTo(face0InitialUVs[i].x + moveDelta.x).Within(0.0001f),
+                $"Face0 vertex {i} X should move by delta");
+            Assert.That(face0FinalUVs[i].y, Is.EqualTo(face0InitialUVs[i].y + moveDelta.y).Within(0.0001f),
+                $"Face0 vertex {i} Y should move by delta");
+        }
+
+        // TEST 2: Verify each vertex in face1 moved by the delta (auto-selected)
+        for (int i = 0; i < face1InitialUVs.Length; i++)
+        {
+            Assert.That(face1FinalUVs[i].x, Is.EqualTo(face1InitialUVs[i].x + moveDelta.x).Within(0.0001f),
+                $"Face1 vertex {i} X should move by delta");
+            Assert.That(face1FinalUVs[i].y, Is.EqualTo(face1InitialUVs[i].y + moveDelta.y).Within(0.0001f),
+                $"Face1 vertex {i} Y should move by delta");
+        }
+
+        // TEST 3: Verify relative offsets within face0 are preserved (no distortion)
+        for (int i = 0; i < face0FinalUVs.Length; i++)
+        {
+            Vector2 finalOffset = face0FinalUVs[i] - face0FinalUVs[0];
+            Assert.That(finalOffset.x, Is.EqualTo(face0InitialOffsets[i].x).Within(0.0001f),
+                $"Face0 vertex {i} relative X offset changed - face was distorted!");
+            Assert.That(finalOffset.y, Is.EqualTo(face0InitialOffsets[i].y).Within(0.0001f),
+                $"Face0 vertex {i} relative Y offset changed - face was distorted!");
+        }
+
+        // TEST 4: Verify relative offsets within face1 are preserved (no distortion)
+        for (int i = 0; i < face1FinalUVs.Length; i++)
+        {
+            Vector2 finalOffset = face1FinalUVs[i] - face1FinalUVs[0];
+            Assert.That(finalOffset.x, Is.EqualTo(face1InitialOffsets[i].x).Within(0.0001f),
+                $"Face1 vertex {i} relative X offset changed - face was distorted!");
+            Assert.That(finalOffset.y, Is.EqualTo(face1InitialOffsets[i].y).Within(0.0001f),
+                $"Face1 vertex {i} relative Y offset changed - face was distorted!");
+        }
+
+        // TEST 5: Verify the distance between face centers is preserved
+        Vector2 face0FinalCenter = Bounds2D.Center(face0FinalUVs);
+        Vector2 face1FinalCenter = Bounds2D.Center(face1FinalUVs);
+        Vector2 finalCenterDistance = face1FinalCenter - face0FinalCenter;
+
+        Assert.That(finalCenterDistance.x, Is.EqualTo(initialCenterDistance.x).Within(0.0001f),
+            "Distance between face centers X changed - faces were recentered!");
+        Assert.That(finalCenterDistance.y, Is.EqualTo(initialCenterDistance.y).Within(0.0001f),
+            "Distance between face centers Y changed - faces were recentered!");
+
+        // Cleanup
+        UVEditor.instance.OnFinishUVModification();
+    }
 }