Use the Ramp macro to define the ramp.
Define a level slab using the same plan profile. This will give identically vertical corresponding points, which can then be snapped onto the ramp using the warping function.Snap by clicking the either the blue down o
r up arrow (but not the square grip though) and dragging onto the corresponding point.Don’t worry about the following warning message. Once all the points are done, it will correct itself.
Delete the ramp to leave the slab only.
Now walls can be attached to the warped slab, openings can be cut and floor finishes added.
A very big thank you to Darren Snook for putting this together.