Automatically Interpolate Z-Values for 3D Polygon Points in Vectorworks

[Nedim]

I have a 3D polygon where the first point is at height 108.90 and the last point at 108.20, with 20 points in between. Is there a built-in method in Vectorworks to automatically interpolate the Z-values of the intermediate points to create a smooth transition between the start and end heights?

What I’ve Tried:

Manually adjusting each point, which is time-consuming.

Experimented with Python scripts (e.g., using vs.SetPolyPtZ() in a loop), but couldn’t achieve smooth linear interpolation.

Searched for existing Marionette or Vectorscript solutions but found no direct fit.

Desired Outcome:
A script or native Vectorworks tool that redistributes Z-values evenly across all intermediate points based on the first and last points’ heights.

Example:

Point 1: Z = 108.90

Point 20: Z = 108.20

Points 2–19: Z-values evenly spaced between these extremes.

Any guidance or solutions would be greatly appreciated!

[Andy Broomell]

Hi @Nedim – Not sure if there's away to get points of a 3D Polygon to do that directly, but one idea that comes to mind is to first put in 22 3D Locus Points to figure out the various heights, and then snap to those. You could utilize the command called "Align/Distribute 3D" (which is different than the "Align Distribute" command). Tap F then start typing the name to easily find the command.

 

Then you probably want to choose Distribute - Spacing under the Z column. Make sure that all the intermediate 3D Locus points are somewhere between the lowest and highest points, and this command will automatically adjust the spacing. Then snap to these when editing the 3D Poly.

 

(There might be other ways, but this is what I'd try)

[VIRTUALENVIRONS]

@Nedim  Can you post this file.  Easier to help the way.  

[Nedim]

@VIRTUALENVIRONS The project consists of circular pools, each made up of multiple segments, onto which I now need to apply 3D polygons of varying heights and convert them into modifiers in order to properly alter the terrain’s appearance.

250721_3D.vwx

[VIRTUALENVIRONS]

Hi Nedim,   I am afraid I still can't see the issue.  I see circular pools, etc. but can't isolate the 3D polygon(s) in question.

 

It may be my limitation, I don't site model the same way you or others do. But, I understand 3D geometry.  

 

If you want to isolate the 3D polygon in question with a little more detail on the "smooth transition", I am happy to look at it.  Or perhaps someone else with more DTM knowledge will understand and help.

Edited July 28, 2025 by VIRTUALENVIRONS

[Tom W.]

5 hours ago, Nedim said:

@VIRTUALENVIRONS The project consists of circular pools, each made up of multiple segments, onto which I now need to apply 3D polygons of varying heights and convert them into modifiers in order to properly alter the terrain’s appearance.

250721_3D.vwx 6.74 MB · 3 downloads

 

Have you considered making the circular pools as Walls then using the 'Create Retaining Wall Site Modifier...' command?

[Nedim]

@Tom W.

I believe that the “Create Retaining Wall Site Modifier” will not provide the desired solution.

 

@VIRTUALENVIRONSThe file might appear unusual to you at the moment, considering it is a working file and the circular pools have been moved outside the DTM for easier handling.

 

The question itself is actually quite straightforward: does anyone have a script that could automate the process of adjusting the elevations of the intermediate points of a 3D polygon between the first and last point? This can be done using 3D points as @Andy Broomell suggested, but I would still prefer to speed up the process.

[Tom W.]

1 hour ago, Nedim said:

 

I believe that the “Create Retaining Wall Site Modifier” will not provide the desired solution.

 

I assumed you were looking for something like this:

 

 

 

[Nedim]

I have sent you a private message 🤑