MultiSubTex mix for Normalmap

[prv_works]

I used a MultiSubTex texture to blend the same image in the diffuse channel but with different rotation mappings:

• Green areas use one mapping
• Red areas use another

The diffuse channel worked perfectly.

However, when I apply the same approach to normal maps:

• Same MultiSubTex distribution
• Output connected to Normal Map node
• Then to my VRayMat's bump input

I get absolutely no relief at all.

Check out my node setup - what could be the issue?
Is this MultiSubTex blending feature for normal maps perhaps not functional yet?

Multisubtex for the difuse works on gpu and cpu.
Multisubtex for the normals works only on cpu...

Captura de pantalla 2025-05-16 170308.png

[prv_works]

Update: Found a working solution! When I replace the Normal Map node with the Normal Bump node, the VRay MultiSubTex blending for relief effects functions correctly, including in GPU rendering mode.

01.png