Variable Rebar not working

[rafael.marinGFHRP]

Hi, i tried making a variable rebar but it is getting out of my stair

On the cut

Also, tried changing positions on the 3D but because the rebair isn't linear, maybe it wont work by changing on the 3D

[jay_colcombe]

Varying Rebar will not work on multi-planar surfaces you would need to use Free-From Rebar and control the length using the constraints method

[rafael.marinGFHRP]

When i try to constraints, im getting error 

and when i tried creating free form rebar im getting error maybe because the lines of my stair aren't on the same spot, i cant create it if it is on the same spot 

[jay_colcombe]

possible it does like a complex arrangement?
One workaround would be to create a Shape/Mass to contain the reinforcement and then hide it from view which removes the complexity of the stair but still look like they are hosted.