Texture Studio

Production guide

OpenGL vs DirectX normal maps

Know when to flip the green channel for Blender, Unreal, Unity, or custom shaders.

Production problem

OpenGL and DirectX normal maps differ mainly in the Y channel direction, so the same texture can light inward or outward in different tools.

Decision checklist

  • Identify the normal convention expected by the target renderer.
  • Flip only the green channel when conversion is required.
  • Test on a sphere or bevel before applying to production assets.

Common failure cases

  • Flipping all RGB channels destroys the normal vector.
  • Fixing the wrong map can hide a shader import problem.

Production FAQ

Which format does Blender expect?

Blender generally expects OpenGL-style normal maps.

Which format does Unreal expect?

Unreal commonly expects DirectX-style Y orientation.