java - Libgdx 3d Rotation another point -

i have problem rotating 3d object constructed of several boxes. here fragment of code 1 box:

mb.part("scianka", gl20.gl_triangles, usage.position | usage.normal,new material(colorattribute.creatediffuse(color.red))).box(2f,2f,2f); 

each box rotates center, need boxes rotate "together"... picture may explain better..

i have 1 idea change origins boxes on common