glsl-specular-blinn-phong

glsl-specular-blinn-phong

Computes the Blinn-Phong specular weight for a light source

Example

#pragma glslify: blinnPhongSpec = require(glsl-specular-blinn-phong)

uniform vec3 eyePosition;
uniform vec3 lightPosition;

uniform float shininess;

varying vec3 surfacePosition;
varying vec3 surfaceNormal;

void main() {
  vec3 eyeDirection = normalize(eyePosition - surfacePosition);
  vec3 lightDirection = normalize(lightPosition - surfacePosition);
  vec3 normal = normalize(surfaceNormal);

  float power = blinnPhongSpec(lightDirection, eyeDirection, normal, shininess);

  gl_FragColor = vec4(power,power,power,1.0);
}

Usage

Install with npm:

npm install glsl-specular-blinn-phong

Then use with glslify.

API

#pragma glslify: blinnPhong = require(glsl-specular-blinn-phong)

float blinnPhong(vec3 lightDir, vec3 eyeDir, vec3 normal, float shininess)

Computes the specular power in the Blinn-Phong lighting model.

• lightDir is a unit length vec3 pointing from the surface point toward the light
• eyeDir is a unit length vec3 pointing from the surface point toward the camera
• normal is the surface normal at the sample point
• shininess is the exponent in the Phong equation (default 20.0)

Returns A float representing the power of the Blinn-Phong lighting equation

License

(c) 2014 Mikola Lysenko. MIT License