three.js/examples/models/gltf/duck/duck0VS.glsl

precision highp float;
attribute vec3 a_position;
attribute vec3 a_normal;
varying vec3 v_normal;
uniform mat3 u_normalMatrix;
uniform mat4 u_modelViewMatrix;
uniform mat4 u_projectionMatrix;
uniform mat4 u_light0Transform;
varying vec3 v_light0Direction;
attribute vec2 a_texcoord0;
varying vec2 v_texcoord0;
void main(void) {
vec4 pos = u_modelViewMatrix * vec4(a_position,1.0);
v_normal = normalize(u_normalMatrix * a_normal);
v_light0Direction = normalize(mat3(u_light0Transform) * vec3(0.,0.,1.));
v_texcoord0 = a_texcoord0;
gl_Position = u_projectionMatrix * pos;
}