# Lighting

Lighting is an important and non trivial part of creating shaders.

### Built in

The library comes with some built in implementations of materials.

#### Lambert

The Lambert material implementation is highly efficient as it only calculated the light at each vertex. It can take a diffuse color and returns an RgbaNode.

```ts
import { lambertMaterial, RgbaNode, rgb } from "@hology/core/shader-nodes"

const color: RgbaNode = lambertMaterial(rgb(0x00ff00))
```

#### Standard

The standard material is based on a physically based rendering approach and looks just like [THREE.MeshStandardMaterial](https://threejs.org/docs/#api/en/materials/MeshStandardMaterial) except it that it does not have features like metalness or refraction.

```ts
import { standardMaterial, RgbaNode, rgb } from "@hology/core/shader-nodes"

const color: RgbaNode = standardMaterial({ 
    color: rgb(0x00ff00), 
    emissive: rgb(0x9f7070), 
    emissiveIntensity: float(0),
    roughness: float(1)
})
```

### Creating your own

Light and shadow information is passed in by ThreeJS based on what exists in the scene and you can access them with uniforms. Check out the / for what predefined uniforms exist and for how to create new ones if some you need are missing.