How to show the horizontal evaluation profile when using SketcvViewModel

[maizhuoying]

I am using SketcvViewModel to draw some "customer graphic" like "Road"

when my users use  SketcvViewModel to location the road (by line-3d), it's hard to location the point on the ground either the SketcvViewModel provides the assist line to show the evaluation profile path。

I found that DirectLineMeasurement3D widget can show the horizontal evaluation profile line when positioning the point。

how to do that? it's impotant for me to optimize my function