attribute vec3 aVertexPosition;
attribute vec3 aVertexNormal;

uniform mat4 prMvMatrix;
uniform mat3 normMatrix;
uniform vec3 directLightDir;
uniform float height;

varying float vLightWeight;

void main(void)
{
	vLightWeight = max(dot( normMatrix *aVertexNormal, directLightDir), 0.0);
    gl_Position = prMvMatrix * vec4( vec3(aVertexPosition.xy, height * aVertexPosition.z ), 1.0);
}