An overlay is a layer visualized on top of the terrain and buildings in the 3D visualization. Overlays can provide spatial insight into specific subject, such as the variation of height and ownership. The visualized properties can originate from the current state of the project or from a result of a spatial calculation.
However, most overlays that can be added to a project use an underlying calculation model, which rasterize the spatial data and apply calculations to it to produce various (intermediate) results. These computational overlays can range from simple distance and average operations to complex water simulations. For these more complex Overlays with multiple results, additional Result child Overlays can be added to the main overlay to store these results.
Overlays available to stakeholders appear as buttons on the right side of the interface. Clicking on any of these buttons will switch the view to the specific overlay. Clicking on the "City" overlay will switch the view back to default. Some overlays are automatically added when a project is created. Some overlays are closely related to indicators, such as Heatstress and Livability.
Parent Overlay
Overlays can be grouped together using a Parent-Child hierarchy. Hovering over any of the Overlays in the Navigation Panel will show additional icons for the Child Overlays of that Overlay.
Every Overlay is considered a Parent Overlay, unless it has a Parent Overlay set, in which case it becomes a Child Overlay of that Parent Overlay. Overlays with Child Overlays cannot be a Child Overlay to another Overlay. Result Child Overlays are always Child Overlays of other Overlays.
When a parent overlay is removed, it's child overlays are not removed, unless the child overlay is a result child type overlay. Otherwise, they simply have no parent overlay set anymore and become a parent overlay themselves.
Grid overlays have the ability to show the difference between the maquette and the current state. The difference visualization uses its own legend, which can also be manually adjusted. The option to show the difference can be turned on or off per Grid Overlay.
Overlays can be given Attributes. Some of these Attributes are used by their calculation model.
Some overlays store multiple timeframes of results. Examples are the Water Overlay and the Heat Overlay. Each timeframe is a complete snapshot of results of the entire project area. These results can be viewed in sequence. When these overlays are visualized in the 2D map, the last timeframe is shown.
Current Situation