Hey,
You should see a ‘ray bounce’ node like in this post…
I tend to move the point down by half the height of the element / geometry bounding box then shoot it. I think there is a BiMorph raybounce node for linked elements.
There are other methods which are more geometry based, but given that there are various floors and your only way to identify which is below them is to shoot the ray, I think that is a fair solution.
I am not sure what you mean by ‘clean’ but you might want to extract some layer data from the floor and adjust your values if your intended offset is from a substrate rather than floor finish.
I hope that helps,
Mark