glsl-specular-ward

glsl-specular-ward

Computes the anisotropic specularity in the Ward model

Example

#pragma glslify: wardSpec = require(glsl-specular-ward)

uniform vec3 eyePosition;
uniform vec3 lightPosition;

uniform float shinyPar, shinyPerp;

varying vec3 surfacePosition;
varying vec3 surfaceNormal;
varying vec3 fiberDirection;

void main() {
  //Light and view geometry
  vec3 eyeDirection = normalize(eyePosition - surfacePosition);
  vec3 lightDirection = normalize(lightPosition - surfacePosition);

  //Surface properties
  vec3 normal = normalize(surfaceNormal);
  vec3 fiberPar = normalize(fiberDirection);
  vec3 fiberPerp = normalize(cross(surfaceNormal, fiberDirection));

  //Compute specular power
  float power = wardSpec(
    lightDirection, 
    viewDirection, 
    normal, 
    fiberPar,
    fiberPerp,
    shinyPar,
    shinyPerp);

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

Usage

Install with npm:

npm install glsl-specular-phong

Then use with glslify.

API

#pragma glslify: ward = require(glsl-specular-ward)

float ward(vec3 lightDir, vec3 eyeDir, vec3 normal, vec3 fiberParallel, vec3 fiberPerpendicular, float shinyParallel, float shinyPerpendicular)

Computes the specular power in the 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 unit length surface normal at the sample point
• fiberParallel is a unit length vector tangent to the surface aligned with the local fiber orientation
• fiberPerpendicular is a unit length vector tangent to surface aligned with the local fiber orientation
• shinyParallel is the roughness of the fibers in the parallel direction
• shinyPerpendicular is the roughness of the fibers in perpendicular direction

Returns A float representing the specular power

License

(c) 2014 Mikola Lysenko. MIT License