Cloudhunter/OpenCCSensors — pull request #109 by CoolisTheName007 (2013-03-15 17:57:22+00:00)
Title: Makes air blocks sonic targets, with minimal changes to the code.

This way users can distinguish between blocks which are hidden / out of range
and air blocks.
Doing the same thing Lua side implies knowing what is a visible block to the sonic sensor, and simulating the raytrace done java-side.
Which is too complicated for the CC user.