My brushed metal and hair highlights look flat and wrong — how are pros doing anisotropic lighting in real-time shaders?

[Chloe Cooper]

I’ve been rebuilding my shader from scratch in Unity and I keep hitting a wall on materials that should have those directional, stretched-out highlights — brushed aluminum, watch straps, wet hair, fur. Right now everything just uses a standard GGX isotropic specular term, so brushed metal looks like it’s made of smooth plastic and my character’s hair looks like a flat green blob instead of catching light along the strand direction. I know the term for this is ‘anisotropy’ and I’ve read a bit about the Blinn hair model and Ward’s distribution, but every tutorial I find either goes super academic or just slaps on a pre-baked normal-map trick that doesn’t actually rotate the highlight as the camera moves.

What’s the actual practical workflow people use to get the highlight to stretch and rotate correctly along a groove/strand direction? Do I need to add a whole separate anisotropic lobe on top of my PBR specular, and how do I feed the tangent vector into it? And for hair specifically, is it worth faking that front-and-back highlight with a subsurface term or am I overcomplicating it? Looking for the real deal, not the ‘just enable anisotropic filtering in your texture settings’ nonsense.

"CPU: i5-13600K"

"GPU: RX 7900 XTX"

"RAM: 16GB DDR5 5600MHz"

"Display: Dell Alienware AW2725DF 360Hz QD-OLED"

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