precision mediump float; attribute vec3 aPosition; attribute vec3 aNormal; uniform mat4 uProj; uniform mat4 uView; uniform mat4 uModel; varying float vLight; struct x { float y; float z; }; void main( void ) { vLight = dot(aNormal, vec3(0, 1, 0)); gl_Position = uProj * uView * uModel * vec4(aPosition, 1); }