That sounds like a lovely challenge. If you want the glow to feel organic, keep the fiber bundles close to the grain of the metal and angle the light just enough so it catches the ridges instead of flatting everything out. A subtle gradient of intensity across the surface will mimic natural light, while precise spacing of the fibers keeps the texture sharp. The trick is balancing the two so the light feels like a natural extension of the material, not an overlay. Just keep tweaking the angles and the light source until it feels like the sculpture is breathing.