Tuesday, April 25, 2017

Top Down Stealth Toolkit Tutorial: How to modify the size of noise pulse emitters

The Top Down Stealth Toolkit uses pulse emitters to display various types of noises. More than just being visual effects, these emitters also provide the added benefit of displaying the audible range of noise stimuli.

The noise pulse emitter's radius is indirectly dependent on two user-defined factors: one being the AI bot's hearing sense radius, & the other factoring in the loudness of the noise itself. By default, the patrol bots have a hearing sense radius 'r' of 500 units. This basically means that a noise event with a loudness value of 'l' (default = 1.0) can be heard by the AI bot up to a maximum distance of 'r*l' units. For example, the footstep noise with a loudness value of 1.0 can be heard up to 500 units, while a different custom noise event with a loudness of 2.0 could be heard from a distance of 1000 units. This maximum distance corresponds to the maximum size of the pulse particle effect.

In order to demonstrate how to edit this value, I'm going to increase the AI hearing sense radius to 800 units & have the same loudness of 1.0 units for the noise event. So first we have to edit the hearing sense radius from the AI Perception component of the Patrol Bot parent class as shown below:

Since the footstep noise loudness is 1.0, I'm not going to edit it. So now we open up the 'P_FootStepPulse' particle system asset & make the following changes:

1. Within the 'Initial Size' module, set the Start Size value to be (1.0, 1.0, 1.0) [the already existing value works as well, but this is easier to understand]

2. Now within the 'Size by Life' module, set the Life Multiplier out value for point 1 to (1600.0, 1600.0, 1.0). This value is basically a multiplier for the initial size value. Point 0 corresponds to the starting value & hence we multiply it's size with the default (1.0, 1.0, 1.0) & while point 1 (which corresponds to final moment of the particle lifespan) multiplies the x & y values by 1600 units thus forming a circular ring of radius 800 units.

With that, you should be able to control the radius of the noise pulse. You can check more learning content at: https://forums.unrealengine.com/unreal-engine/marketplace/68942-top-down-stealth-toolkit?p=639125#post639125