Create Detla Terrain Model tool

Used to create a delta terrain model between a surface and plane or between two surfaces, which can then be used for Isopach contouring.

Found on the Civil ribbon in the Terrain Model group.

The Delta Surface tool creates a delta TM between a surface and plane or between two surfaces, which can then be used for Isopach contouring. The Z value in the delta TM is the difference between the two specified models or model and surface, rather than actual elevations. Any voids in any of the terrain models produces a corresponding void in the delta model (as the software cannot compute the difference in these areas).

Note: It is prudent to use a Feature Definition unique from the original TM, so each can be distinguished, as the delta TM is on top of the original TM when reviewing in a Top View.

Tool Settings

Setting

Description

Delta Method

Terrain Model to Terrain Model – specify two files
Terrain Model to Plane – specify one file and an elevation

Vertical Offset 1

Vertical Offset 1 moves the first terrain model up (positive value) or down (negative value) by the offset distance, in terms of master units prior to processing the delta command.

Vertical Offset 2

Vertical Offset 2 moves the second terrain model up (positive value) or down (negative value) by the offset distance, in terms of master units prior to processing the delta command.

To Plane

The elevation of the plane specified in terms of master units (feet or meters).

Feature group

Setting	Description
Feature Definition	Select an existing feature definition from the drop-down list to use for object being placed.
Name Prefix	Type a prefix value to use for all objects set using this Feature Definition, which are useful in quickly identifying features in a group.

Key-in: terrainmodel delta