generating lines from one point that will stop at obstacles

Hey guys. would kindly appreciate some help:

Am trying to investigate an architectural site and what can be seen and cannot be seen from one point.

am trying to start with one point

and have lines at for example every 30 degrees from the point spreading out in space. however, if the lines reach a surface/object drawn in rhino/grasshopper the lines stop.

heres a hand drawn diagram of what i'm trying to generate in grasshopper.

thanks in advanced!