The Material Function WorldCoordinate3Way seems to incorrectly perform the Lerps from the axis contributions of the normals. An example is show here, with the left objects using the version that comes with Unreal. You can see in the top portion of the cube that the top face has bleed-in from the Y texture even though there should be no Y component in a Z plane. This causes very noticeable artifacts as can be seen.

The issue is that the amount of axis contribution of the normals is not taken properly into account for the Lerps. Here is a possible solution which corrects the issue. This replaces the inputs to the two LERP function in the existing material function.

The user has provided a fix solution which is included in the attached images. I have created a test project

Steps to Reproduce

1. Open attached project.
2. Open the M_3Way_Inst material instance.
3. Increase the Blend Mult X and Blend Mult YZ parameters to 2.0

Outcome Artifacts begin to appear in the material.

Expected Multiplies the blend between the sides.

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Affects Versions4.11.24.12
Fix Commit2983743
Main Commit2998067
CreatedMay 18, 2016
ResolvedMay 19, 2016
UpdatedJul 14, 2021