Wednesday, December 21, 2016

Top Down Stealth Toolkit Tutorial: How to create customized Laser Security Systems

[The following information is based on the v1.4 edition of Top Down Stealth Toolkit & hence may not remain entirely relevant in later versions. For more information about the toolkit, check out the official support thread in the Unreal Engine forums:]

The Laser Security Systems in Top Down Stealth Toolkit function as an auxiliary layer of AI Threat Detection by alerting all nearby patrol bots upon being intercepted by the player. The underlying logic is a simple combination of Timeline based movement & Collision Overlap checks. These actors support drag & drop functionality from the editor & can be easily customized using the variables exposed to the editor from the blueprints. This post goes over the impact of the aforementioned parameters on the working of Laser Security Systems.

1. Length: The Laser Security System uses a box collision component to determine if the player is within it's range. The length parameter determines the total length of this box & also controls the area covered by the laser particle system.

2. Max Height: As described in the tooltip, this variable determines the max height up to which the lasers move relative to the default position at which the actor has been placed in the level.

3. Player Height: The Player Height parameter is used to control the color of the laser based on it's position relative to the ground. Red color indicates that players passing through the laser will trigger an alarm while white color indicates that the laser tracker has moved up beyond the player's height & thus enable safe passage below it. This can be quite useful in top down games, as perception of the location of actors that move along the z plane may not always be intuitive to the player.

4. Alarm Timer: The Alarm Timer value determines how often the alarms are triggered while the laser system has an active target. Since the range of alarm noises are limited, having a timed alarm system can improve the chances of alerting nearby AI patrol bots.

5. Movement Timeline Starting Time: This parameter determines the starting location of the laser along it's movement trajectory. It has a range of 0.0 to 4.0, with 0.0/4.0 representing the starting position [i.e. the location at which the actor was placed] & 2.0 representing the highest position along it's movement trajectory. Anything between 0.0 & 2.0 implies that the laser will have an upward motion going towards the highest point along the trajectory, while a value between 2.0 & 4.0 means that it will have a downward motion going towards the lowest point or the starting position along the trajectory.