Existing vs Proposed terrain, Site modifiers and multiple DTMs

[RG-AP_HBeck]

Hello, first time posting here! I hope someone here can shed some light on an issue I'm having trying to figure out how to create a "proposed" site model.

 

First of all, I just started using Vectorworks, so bear with me. 

I have this complex sloped terrain that we're trying to smooth out by using retaining walls. I watched some tutorials and managed to easily create the "existing" DTM from 3d contours that I imported from CAD. Editing the "proposed" contours, however, took ages, and they ended all over the place after exiting the "edit mode". So I went back to CAD and designed the proposed contours there. I used the same process as I did when I imported the existing terrain and the model looks good.

 

The problem is: I now have 2 site models, an "existing" one and a "proposed" one, instead of having both on the same DTM, and I need to create comparative sections and cut and fill calculations. Every method I try has resulted in the proposed contours just going all over the place.

 

I tried using site modifiers (on their own layer, and within the Site-DTM-Modifier class) by importing the proposed contours dwg to another VW file, converting them into 3D polygons and copying them into the original file, all within a Grade Limit site modifier (which isn't intersecting with any of the 3d polys). This resulted in this complete mess (the baby blue contours are the site modifier.)

Which translates to this 3D:

 

Here is the DTM I created from the proposed contours and what I actually want it to look like:

 

 

I've also tried to delete the "proposed" contours on the first DTM through the edit mode and replaced them by copying the ones from the second DTM. For some reason they all reset to 0 elevation. I tried to correct the elevation manually on every single contour, but after exiting the "edit mode" it just turned into a complete mess, even worse even than when trying to use site modifiers.

 

I feel like I'm missing something here and I'm running out of time. All the tutorials I find are dealing with way simpler site models/designs. Please help me.

[Pat Stanford]

Take a look in the manual for "Snapshots" of DTMs.  This will let you display the model as Existing, take a Snapshot, then change the model to Proposed so you can view them at the same time.