First of all: create 2 Boxes (Poly or Nurbs doesn't matter) !
The 1st Box is a liitle bit larger than the 2nd.
create a point-light (a Maya default one) !
Set: Turn on "Emit Photons" under
Caustic and Global Illumination !
Exponent : 1
Physical : off
Create a sphere (Poly or Nurbs doesn't matter) and place it right below the pointlight !
now create a small plane and place it beneath your pointlight so that the
normals show toward
the sphere and the pointlight!
name this object 'PhotonCollector' !
Place a camera inside the inner box - so that you can see the sphere !
Modeling is done ! -> lets continue with the shader assignment !