warpNoise3D

//! requires noise3D
fn warpNoise3D(x: vec3<f32>, seedVal: f32) -> vec3<f32> {
  var p = x + seedVal;
  var nx = 0.0;
  var ny = 0.0;
  var nz = 0.0;
  var w = 0.5;
  
  for (var i = 0; i < 3; i++) {
    nx += w * noise3D(p);
    ny += w * noise3D(p + vec3<f32>(13.5, 41.3, 17.8));
    nz += w * noise3D(p + vec3<f32>(31.2, 23.7, 11.9));
    p *= 2.0;
    w *= 0.5;
  }
  
  return vec3<f32>(nx, ny, nz) * 2.0 - 1.0;
}