// --------------------- Terrain material ------------------------

// IN
attribute vec4 vertex; // iPosition
attribute vec2 uv0;    // iUv
// OUT
varying vec3 vUv;
// UNIFORM

void main(void)
{
   gl_Position = gl_ModelViewProjectionMatrix * vertex;

   vUv.xy = uv0;
   vUv.z = vertex.y;
}