How to keep the same visual effect of two objects?

Hi,
I copied aMesh as bMesh, put bMesh into Billboard, just put it in how to keep the visual effect of aMesh and bMesh consistent , how to calculate the position and quaternion of bMesh?

<aMesh/>
<Billboard>
  <bMesh/>
</Billboard>

The Billboard is always face the camera.
Thanks!

visual effect? i think this needs more description. billboard makes it face the camera regardless of position, similar to a sprite.

Hi Drcmda:
same question

I found a solution that can solve my problem, the implementation of this seems to be inelegant