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Line-of-sight behavior

Published 21 Aug, 2017
394 words
~2-3 mins

The Line-of-sight (LOS) behavior allows the ability to check if two objects can "see" each other. More precisely, it will check if there are any obstacles blocking a line between the two objects. Click here to open an example of Line-of-sight.

Line-of-sight properties

Obstacles

Whether to use Solids as blocking line-of-sight, or Custom, where the objects blocking line-of-sight must be added using the Add obstacle action.

Range

The maximum distance in pixels that line-of-sight can reach. If an object is further away than this distance, the object will never have line-of-sight to it, even if the intervening space is clear.

Cone of view

The angle of the cone of view in which the object can have line-of-sight to other objects, relative to the current angle of the object. For example if this is 180, then the object can have line-of-sight to any objects anywhere in front of it, but never behind it. If 360, the object can have line-of-sight to objects at any angle.

Use collision cells

Whether to use the collision cells optimisation when testing line of sight. Usually this is faster, but in some cases over extremely long distances it can be slower.

Line-of-sight conditions

Has LOS to object

Check if the object currently has line-of-sight to another object. For the condition to be true, the object must be within range, within the cone of view, and with no obstacles in the way of a straight line between the two objects. This condition also picks the instances of the chosen object that are in the line of sight.

Has LOS to position

Check if the object currently has line-of-sight to a position in the layout. For the condition to be true, the object must be within range, within the cone of view, and with no obstacles in the way of a straight line between the two objects.

Line-of-sight actions

Add obstacle

If the Obstacles property is Custom, adds an object type to count as an obstruction to line-of-sight.

Clear obstacles

If the Obstacles property is Custom, clears any object types added as obstacles with the Add obstacle action.

Set cone of view

Set range

Sets the corresponding behavior properties. For more information, see Line-of-sight properties.

Line-of-sight expressions

ConeOfView

Range

Retrieve the corresponding behavior properties. For more information, see Line-of-sight properties.