This tool merges two normal maps using 3D vector rotation mathematics to properly combine surface details. The base normal map defines the primary surface orientation, while the add normal map overlays secondary details like wrinkles, scratches, or patterns.

The mask image controls the intensity per-pixel: black (0) removes the effect, white (255) applies full effect. If no mask is uploaded, the Intensity slider uniformly controls the blend strength across the entire image.

Examples: Combine "brick details" with "wall texture" for buildings, or "wrinkles" with "fabric".

The alpha channel is blended for per-pixel specular exponent values (brighter = shinier). Ensure the Advanced Lighting Model is enabled to see effects. Use OpenGL (Y+) for compatibility.

Note: Per-pixel specular exponent is experimental and may not work as expected in some systems. Consider PBR Materials for modern projects.