Beacon beams are transparent from the inside

The Bug

Beacon beams are transparent from the inside. Only the translucent texture around the actual beam is visible when standing inside of a beam.

Steps to Reproduce

1. Construct a beacon and power it
2. Stand inside of the beacon beam

Observed Behavior

Beacon beams are rendered transparent from the inside.

Expected Behavior

Beacon beams would not be rendered transparent from the inside. Instead, they should be rendered opaque on the inside, just like how they appear on the outside.