In 3d modeling by point clouds it is often necessary to change the Z-coordinate of the selected object: whether it is a polygon or a polyline.

I have created a function in LISP language in autocad to change the elevation of the selected object:

• by first or last point
• by lowest or highest point
• by average value of the elevation
• change the elevation of all vertexes by changing the elevation of the first and last point of the object.

The ZAPPROX command replaces the Z-values of the vertices of a selected 3D polyline based on interpolation or user-defined methods. It’s typically used to smooth, approximate, or normalize elevations (Z-values) across a polyline. It’s useful for terrain modeling, elevation smoothing, or contour editing in AutoCAD.