function p2d = project( p3d, cam, align_mat )
  
  p2d = [];
  ncams = length( cam );
  
  for c = 1:ncams
    
    % Project to 3D video referent
    xyz = inv( align_mat ) * p3d;
    
    % Euclidian projection
    new_x = cam( c ).Pmat * xyz;
    new_x = new_x ./ repmat( new_x( 3,:), 3, 1 ) ;
    
    % Apply radial distortion
    new_xd = doradial( new_x, cam(c).K, cam(c).kc, cam(c).alpha_c );
    
    p2d = [ p2d; new_xd ];
    
  end