I have struggled a long time now, to get to know what kind of fixture I should use if I have something on four legs against a floor.

When I look at examples they always use fixed geometry, but that is not true, all four legs can move. So how should I solve this?

If I use immovable it is not completly true either. I can only use roller/slider if it is a solid, and not a beam. But to do this calculation in a solid, it takes to much time, if it is even possible.

So then I come to use reference geometry in beam. Is that the "true" way to do it? And how should I set that up?

Thanks in advance