CAD plans typically require editing and restructuring before they are suitable for importing into LEGION Model Builder; this process is termed 'cleaning' Two main types of CAD are used within LEGION Model Builder:

• Presentation CAD
• Simulation CAD

Presentation CAD lines provide useful contextual information about the pedestrian venue but they are not true obstacles; examples include:

• Text
• Stair flights and landings
• Escalator landings, comb lines and work points

Presentation CAD can also provide useful reference points for object snaps when creating and placing Activity Objects.

Simulation CAD lines represent objects that are genuine obstacles to pedestrians; examples include:

• Walls
• Balustrades and railings
• Ticket gates
• Windows
• Door leaves
• Furniture
• Vehicles