Specular Lighting

Specular lighting models glossy surfaces.

\[\V{c}_s=\V{c}_l\,\max(\V{n}\cdot\V{h}, 0)^\alpha\]

The color of the light $\V{c}_l$ is modulated by the dot product of the normal $\V{n}$ and half-angle $\V{h}$ vectors, raised to a power.

A graph from $-\frac{\pi}{2}$ to $+\frac{\pi}{2}$ of $(\V{n}\cdot\V{h})^\alpha$ for $\alpha=0$ in black, and $\alpha=1, 2, 4, 8, 16, 32, 64$ in red.

That power $\alpha$ determines the tightness of the distribution of color.

A higher power gives a shinier material.