Combo Overlay tutorial

Prerequisites

The following prerequisites should be met before starting this tutorial:

• This tutorial relies on base knowledge about the editor interface and the creation of Overlays. If you have not yet followed the tutorials related to those subjects please do so first.
• This tutorial can be followed with any project of any arbitrary location, preferably with both roads and traintracks. 

Preparations

Take the following steps as preparation for following this tutorial:

• Start your project. This can be a pre-existing project, or a newly created project.

Introduction to the Combo Overlay

The Combo Overlay is a Grid Overlay which allows for the creation of custom spatial calculation models. It is comparable to raster calculators which can be found in other GIS packages such as QGIs. The principle on which it operates is that for each grid cell, other Grid Overlays may provide values, and the combo Overlay uniformly applies a (simple or complex) formula to compute a new resulting value for that grid cell, and does so for all grid cells.

Creating a simple masking calculation

To get started with a Combo Overlay, it is basically always neccesary to have some other Grid Overlay in the same Project to run a calculation on.

Add a Traffic Noise Overlay.

Editor → Current Situation (Ribbon tab) → Overlays (Ribbon bar) → Environmental → Traffic Noise (Dropdown)

This Traffic Noise Overlay will serve as the primary input to work with. It computes results based on built-in formulas for noise from traffic. Although it's possible to tweak the inputs and the legend of the resulting Overlay, the principles of the calculation and the results thereof are immutable.

Add a Combo Overlay.

Editor → Current Situation (Ribbon tab) → Overlays (Ribbon bar) → Custom → Combo (Dropdown)

The Combo Overlay accepts a set of inputs, which are Grid Overlays.

Notes

• The legend of the first input is automatically read out by the Combo Overlay as the default legend. It is still possible to create a custom legend.
• The editor interface will generally present the first 3 inputs (A, B, and C) of the Combo Overlay. However, a total of 10 inputs can be added and used, by switching to the "inputs" tab.
• It is possible to link multiple Combo Overlays together by setting one as input for another. This way, intermediate results can be computed and presented, but also more complex calculations can be created and/or split up into managable sub-calculations.