Indoor Airflow Sim not Displaying Vectors

Hi all

Running Grasshopper 1.0.0008 and Rhino 8 SR4

I haven’t worked in Grasshopper for a few years now and even then we were never well acquainted. I’m trying to simulate indoor airflow using Butterfly and have followed this tutorial. The only difference is that in the tutorial his building uses surfaces, whereas I have used breps.

When I run the simulation I receive no errors, however, I don’t see any output in Rhino. The output I am looking for is a grid of arrows showing the flow of air. I’m a new user so can’t upload files, sorry so I can’t give you any more than that.

Thanks in advance.