Setting stairs as a diagonal constraint

[Anonymous]

Hi, 

I have this stair core that 3 cubic volumes intersecting with it, 

How can set the diagonal as a constraint for the intersection ? 

Any ideas? 

[Alfredo_Medina]

It's not clear what you want to do. However, let me say this: one way in which you can use the slope of the stair as a constraint is with a baluster family. I hope that helps.

[Anonymous]

Thanks for replying. 

It's just a matter of 'modeling mass in place'. Didn't know the option as a beginner. 

In the case above there is no way to intersect the geometries ...