Beckmann specular distribution for GLSL
npm install glsl-specular-beckmann``glsl
#pragma glslify: beckmann = require(glsl-specular-beckmann)
uniform vec3 eyePosition;
uniform vec3 lightPosition;
uniform float roughness;
varying vec3 surfacePosition;
varying vec3 surfaceNormal;
void main() {
vec3 eyeDirection = normalize(eyePosition - surfacePosition);
vec3 lightDirection = normalize(lightPosition - surfacePosition);
vec3 normal = normalize(surfaceNormal);
float power = beckmann(lightDirection, viewDirection, normal, roughness);
gl_FragColor = vec4(power,power,power,1.0);
}
`
Install with npm:
`
npm install glsl-specular-beckmann
Then use with glslify.
`glsl`
#pragma glslify: beckmann = require(glsl-specular-beckmann)
##### float beckmann(vec3 lightDir, vec3 eyeDir, vec3 normal, float shininess)
Computes the specular power in the Beckmann model
lightDir is a unit length* vec3 pointing from the surface point toward the lighteyeDir
is a unit length* vec3 pointing from the surface point toward the cameranormal
* is the surface normal at the sample pointroughness
* is a parameter between 0 and 1 measuring the surface roughness. Small values are shinier, larger values are rougher.
Returns A float` representing the specular power