Skip to main content

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: https://forums.unrealengine.com/showthread.php?97156-Top-Down-Stealth-Toolkit]


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.

Popular posts from this blog

Unreal Engine 4 Tutorial: Smooth Zoom using Mouse Wheel for Top Down Template

Well, I had already written a tutorial for implementing Smooth Zoom functionality for Top Down Template. But it was based on keyboard inputs. Since most Top Down PC games use mouse wheel for zoom, I decided to make a tutorial for the same. The core logic here is the same as the one implemented by Ryan Jon for the custom camera in his RTS Community Project. If anyone's interested, they can get the code for the RTS Community Project here:

UE4 RTS Community Project

Anyways, he has replaced the default camera for the characters with a general camera since that's more ideal for developing an RTS game. Since a basic Top Down game with a single playable character does not need a separate custom camera, I decided to implement the same functionality for the default player camera in UE4's Top Down Template. So let's get down to it.

First of all we need to make a custom curve from the content browser. We will be using this curve to define the smooth camera movement while zooming …

Unreal Engine Tutorial: Create Circular Ring Material without Textures

Hi, welcome back for another tutorial. It's been quite a while since I put up a tutorial as I've been busy working on toolkits for the Marketplace. One of my earlier tutorials [link: Unit Selection Decals for RTS Games] had focused on how to create ring materials using textures, as well as using them to display unit selection decals for RTS games. However, a drawback associated with using textures was that it prevented the user from changing the inner & outer radius of the ring. And during prototyping stages of a product, it's far better to implement structures that can be changed easily from within the engine so that you don't have to create a new asset from an external package every time you need to test out a new idea. I've found this approach quite useful while working on my own products. Hence, this tutorial focuses on creating a ring material that can be adjusted both from within the material editor as well as dynamically at runtime.

Alright before we get …

Unreal Engine Diaries #11: Nav Mesh Configuration

[This episode of Unreal Engine Diaries focuses primarily on nav mesh configuration, nav areas & configuration of agent types.

Source: Unreal Engine 4 AI Support Twitch Broadcast with Mieszko: https://www.youtube.com/watch?v=7LaazCv4rB0]

1. The Recast NavMesh has a couple of attributes named 'CellSize' & 'CellHeight' under the 'Generation' section in it's details panel. Together they determine the resolution of the nav mesh & lowering these values can create more precise nav meshes. It could be especially useful when there are lot of holes in the nav mesh due to the surface properties of the terrain. However, lowering them also makes the nav mesh calculations more expensive.

2. If runtime nav mesh generation is enabled, it would be best to set the 'Tile Size' attribute of Recast NavMesh to the minimum viable amount.
3. The 'Min Region Area' parameter which can also be found under 'Generation' section of Recast NavMesh can be i…