Noise Functions

Learn various noise function implementations and applications as the foundation for procedural texture generation.

Learning Objectives

- Understand characteristics of different noise function types

- Learn to implement basic noise algorithms from scratch

- Master noise function applications in texture generation

Key Concepts

Pseudo-Random Number Generation

Creating randomness in shaders:

`glsl

float random(vec2 st) {

return fract(sin(dot(st.xy, vec2(12.9898,78.233))) * 43758.5453123);

}

`

Value Noise

Interpolation based on random values at grid points:

1. Generate random values at grid points

2. Use bilinear interpolation for smooth transitions

3. Produces continuous noise fields

Gradient Noise

Higher quality noise based on gradient vectors:

- Store gradient vectors at grid points

- Calculate distance vectors to grid points

- Use dot products and interpolation to generate noise

Noise Applications

- Texture Generation: Wood grain, marble, clouds

- Terrain Generation: Height maps, erosion effects

- Animation Effects: Fire, water waves, particles

Exercise

Implement a basic value noise function and use it to create organic textures.

Hints

1. Start with a simple random function

2. Implement grid coordinate calculations

3. Generate random values at grid corners

4. Use smoothstep for interpolation

5. Combine multiple scales of noise

Expected Result

You should see smooth organic textures with natural random variations that can serve as the foundation for various materials.