Hi,
I'm continuing to trouble shoot my way through my first attempt at a matchmove project from Boujou to Houdini. The scene involves a short clip of a set of stairs in my house, down which I wish to throw some water. Sounds simple enough in my head, though I'm running into probelm after problem at the min.

So far, I've build my stairs up in Houdini, using the cam from the Boujou track. The track wasn't perfect in the first place, but will do for now so I can get my head around the principles of this workflow.

My problem arises when I try to introduce the water into the scene. It reacts initially with the null points (I think that's what they're called?) from the camera track, ie. the reference crosses in 3D space. No big issue, I turn their visibility off, yet the water now seems to interact with the step in a different position of 3D space. Basically, it's not hitting the step, it's somehow hitting an invisible point above the step, probably twice it's height in the air.

Wasn't sure if this would ring any bells on such a project? Or if anyone would be good enough to take a look at the project file for me? I'll upload if so

Thanks in advance.
Chaz