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

[varinotmUnity]

DO NOT FORGET TO INCLUDE A CHANGELOG ENTRY

Purpose of this PR

Fix UV Editor distortion when dragging connected texture group faces

Problem

When you select one face in a subdivided/connected texture group and drag it in the UV Editor, all connected faces would visually jump/distort during the drag. On mouse release everything snaps back to correct position, so it's visual bug only.

Root Cause

OnBeginUVModification() auto-selects all faces in the texture group, then calculates new pivot as center of ALL faces. The move math then reprojects each vertex relative to this new center, causing the visual jump.

Fix

Store handlePosition BEFORE the texture group auto-selection loop runs. Use this original position as uvOrigin instead of the recalculated center.

This way connected faces maintain their spatial relationship to the original pivot point, meaning no distortion.

Changes

• UVEditor.cs: Save original handle position before SelectTextureGroups(), use it for uvOrigin
• Cleanup: Use EditorGUI.actionKey instead of platform-specific Control/Command key check. This is only because Unit tests were failing.
• Tests: Added MoveSingleFace_PreservesRelativePositions() and MoveConnectedFaces_PreservesRelativePositions() to verify no distortion happens. The unit tests do not test the original issue, as it is ONLY happening in the editor UV window. The editor calls MoveTool(), while the unit tests calls SceneMoveTool. The tests were mostly added to make sure I didn't break the API.

Links

https://jira.unity3d.com/browse/PBLD-276

Comments to Reviewers

Though I did not test what would happen with the rotate and scale tool. From my testing, it looks fine, but thorough testing from QA might be necessary to make sure we don't cause regression

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[u-pr-agent]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🎫 Ticket compliance analysis 🔶 PBLD-276 - Partially compliant Compliant requirements: The PR addresses the snapping issue by correctly preserving the handle position when the selection is programmatically expanded to include the entire texture group. Non-compliant requirements: [] Requires further human verification: As noted by the author, the impact of this change on the Rotate and Scale tools in the UV Editor has not been thoroughly tested and requires manual QA to ensure no regressions were introduced.

⏱️ Estimated effort to review: 2 🔵🔵⚪⚪⚪ The PR includes a small, targeted logic change and well-structured unit tests, making it relatively easy to understand and review.

🏅 Score: 95 The code provides a clean fix for the reported bug, significantly improves test hygiene, and adds excellent regression tests, but manual testing on related tools is still required.

🧪 PR contains tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Handle Position Logic The core fix involves caching the handle position before the selection is expanded and the editor is refreshed, then restoring it. Please validate that this logic correctly prevents the "snapping" behavior described in the ticket without introducing side effects during UV modification. 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) ); // kinda lame... this will cause setSelectedUVsWithSceneView to be called again. if (fc != selection[i].selectedFaceCount) update = true; } selection[i].ToMesh(); // Reset the Mesh to PB data only. selection[i].Refresh(); } if (update) { // UpdateSelection clears handlePosition ProBuilderEditor.Refresh(); SetHandlePosition(originalHandlePosition, true); } Test Cleanup The TearDown method has been significantly improved for better test isolation. This is a great addition that improves the stability of the test suite. [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>(); // 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(); }

Update review

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[u-pr-agent]

Suggestion: The new tests MoveSingleFace_PreservesRelativePositions and MoveConnectedFaces_PreservesRelativePositions are missing a call to OnBeginUVModification() before SceneMoveTool(). The bug fix in this PR is located within OnBeginUVModification, which handles auto-selecting grouped faces and preserving the handle position. Without this call, the tests do not accurately simulate the user workflow and fail to validate the actual fix. [possible issue, importance: 9]

Suggested change

	// Simulate a move operation
	Vector2 moveDelta = new Vector2(0.1f, 0.2f);
	UVEditor.instance.SceneMoveTool(moveDelta);
	// Simulate a move operation
	Vector2 moveDelta = new Vector2(0.1f, 0.2f);
	UVEditor.instance.OnBeginUVModification();
	UVEditor.instance.SceneMoveTool(moveDelta);

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[varinotmUnity]

SceneModeTool called OnBeginModification already

[codecov-git.colasdn.top]

Codecov Report

All modified and coverable lines are covered by tests ✅

@@            Coverage Diff             @@
##           master     #631      +/-   ##
==========================================
+ Coverage   35.55%   36.02%   +0.47%     
==========================================
  Files         277      277              
  Lines       34889    34888       -1     
==========================================
+ Hits        12406    12570     +164     
+ Misses      22483    22318     -165     

Flag	Coverage Δ
mac_trunk	34.59% <100.00%> (-0.75%)	⬇️
win_trunk	34.49% <100.00%> (-0.75%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
Editor/EditorCore/UVEditor.cs	39.78% <100.00%> (+6.08%)	⬆️

... and 6 files with indirect coverage changes

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[varinotmUnity]

the cube was not getting deleted at the end of the test. the changes here is to clean the test. only this line was necessary to fix the issue though

[varinotmUnity]

this was changed or else the test would not pass