next remove the light, and render just with the glowing  4 balls ( click)

Render settings,
cast shadows ON
raytrace ON
bounces 2
IC 10
IQ 50
Pixel 3
MSR 0.5
And this is the result: (click)

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!