c_trace USE_POLYGON not working with animated polygons

I'm using this code to determine the surface of my ocean which is an animated model. The c_trace works fine without animation, but when I animate is only returns the original polygon positions.

How do I determine the real polygon positions?

You can use c_updatehull.
It recalculates collision hulls for the given entity to match the vertex positions of a certain frame.

Thanks for the quick response. I'll try it out!

Yes, that works. But c_updatehull is very slow, so you don`t can use it every frame