A reliable workflow
Treat Y− as a starting point, not proof
The Y− preset is a practical starting point for Unreal Engine workflows, while Flip Green Channel remains a corrective import option.
Check the material Normal path
Connect the sampled texture to the material Normal input and verify that the sampler and compression are recognized for normal data.
Validate with movable directional light
Movable directional lighting reveals inverted relief more clearly than a flat environment or a texture-editor thumbnail.
Prepare and import a normal map for Unreal Engine
A Y− export is a practical starting point for a normal map for Unreal Engine, but baker presets, plugins, and previous conversions can change what the file actually contains. Import the lossless texture, confirm that Unreal recognizes normal-map compression and non-sRGB vector data, and inspect the green-channel option instead of applying it blindly. Connect the texture sample to the material Normal input. Do not connect tangent normals to Base Color or treat their purple appearance as evidence that the normal map for Unreal Engine has the correct orientation.
Diagnose the mesh and build conditions
Test a normal map for Unreal Engine with a movable directional light and an asymmetric raised feature. If the vertical response is inverted, compare the import Flip Green Channel state with the export convention. If seams follow UV borders, investigate tangent basis, smoothing splits, mirrored islands, and the bake mesh before editing pixels. Review texture resolution, mip behavior, compression, sampler type, and target scalability on the intended platform. Recording those settings alongside the normal map for Unreal Engine makes later reimports and material changes repeatable instead of relying on a thumbnail judgment.