Types of layer

There are four types of layer within LEGION Model Builder:

CAD Layers
Activity Object Layers
Partition Layers
Analysis Layers, including the Conditions Layer (Model Builder)

Whenever you create a new model within LEGION Model Builder, a default CAD Layer; default Activity Object Layer and default Conditions Layer are created. Layers are listed in both the Object Directory and the Layer directory. Similarly, when you open a project in LEGION Simulator, a default Analysis Object Layer is created.

CAD Layers

A CAD Layer stores CAD that has been imported into, or drawn in, LEGION Model Builder. It may contain either Presentation CAD or Simulation CAD (see Preparing a CAD plan).

Each CAD Layer has two tabs, labelled Properties and FDS.

Properties

Name.
A check box labelled Use in simulation, which enables you to use the contents of this layer as part of a simulation. CAD segments included in simulation layers will be treated by Entities as obstacles.
A check box labelled Use for Auto-navigation, which enables you to include or exclude the contents of the layer from the Auto-navigation process (this will enhance performance). Auto-navigation is also known as "Macro-navigation".
The number of CAD objects stored in the layer.
An attribute to indicate whether the layer contains imported CAD or user-drawn CAD.
(If the layer contains imported CAD) the filename of the imported file along with the date and time it was imported. When you import a .dxf, .dgn or .dwg file, you are presented with the option to retain any existing layer structure in the file.

FDS

This tab enables you to use the CAD objects on this layer as part of a file to be used with the FDS software (see y for further information).

There are only two parameters to set on this tab:

A check box labelled Include CAD in FDS file, which enables you to include the CAD in this layer as part of the file you will export for use with the FDS software.
A box labelled Height of CAD, which enables you to enter a height in metres for the CAD walls (this is also known as the z-coordinate).

A note about the Use for Auto-navigation option

When this option is unchecked, Auto-navigation will ignore all CAD objects on the layer when calculating possible paths for Entities. Entities will still negotiate the objects when they encounter them during the course of a simulation. Focal Drift Zones and Queue Groups will also ignore these CAD items when their visibility polygons are generated.

Ignoring these small CAD objects can significantly reduce the calculations that Auto-navigation has to perform, thereby enhancing performance. We advise you to create a layer or layers exclusively containing such small objects so that it is easy for you to identify them and include or exclude them from Auto-navigation.

When this option is checked, Auto-navigation will consider all CAD objects on the layer when calculating possible paths.

Activity Object Layers

An Activity Object Layer stores Activity Objects, like Delay Points, Queues, Stairs, etc. Such objects may be arranged over several Activity Object Layers to allow for easier management of objects.

An Activity Object Layer has a:

Name.
List of Activity Objects stored in the layer.

Partition Layers

Partition Layers are useful when you need to override LEGION’s Auto-navigation system and place Focal Drift Zones to provide routing instructions instead. This can be done using Interactive or Batch partitioning (see "Focal Drift Zone partitioning" in Focal Drift Zones for details).

Before you can place Focal Drift Zones, you need to specify a unique target object for the Partition Layer. See Selecting a target for the Partition Layer .

Analysis Layers

An Analysis Layer stores Analysis Objects: Analysis Lines, Poly-lines and Zones. It contains a:

Name.
List of Analysis Objects stored in the layer.

Conditions Layer

The Conditions Layer is an Analysis Layer that is created by default whenever you create a new Model. It stores any Analysis Objects which you place in order to introduce Conditions into a model. For more information, see Conditions in Models .