Chaos and Shooting, Houdini and Niagara Forever

[UnitFX]

Hello everyone. I recently spent some time studying the Chaos destruction system and wanted to share some of the things I managed to learn.

Most of it is fairly technical and probably more relevant for a technical artist than for a VFX artist, but I plan to combine it with shooting effects, so it might turn into something interesting.

Destruction in Unreal is not very well documented. There is very little information that quickly helps you understand how the system works or how to solve seemingly small issues that actually have a strong impact on performance. Most of the material I found focuses on workflows that do not use the newer Dataflow system.

I had to go through all the official talks on this topic, as well as forum discussions and examples created by other users. The most valuable resource turned out to be the ContentExamples project — I spent a lot of time there simply analyzing and testing things.

This won’t be a tutorial. It’s more of a portfolio piece accompanied by some of my thoughts and observations.

Planned tasks include creating a destructible column, impact effects, and shooting effects.
Additional effects will appear during the destruction itself. The idea is to slightly extend the visual complexity by adding small lightning discharges that briefly appear inside the breaking object.

The destruction will not be fully simulated. The goal is partial destruction, where only certain parts of the object break.

And another task with an asterisk. Most likely it won’t work, but maybe I’ll be able to figure it out. The idea is to place interactive elements near the column that explode when hit and cause part of the column to break as a result.

[UnitFX]

Before starting this project, the goal was to prepare a level with pleasant lighting and a third-person character that already had a working weapon and shooting system inside a default Unreal project.

The first thing I tried was GameAnimationSample, and I immediately liked the animations there and the Paragon character. I spent about a week — a fairly difficult week — trying to understand how the animation system works and how to quickly assemble a prototype like this. My first attempt was to build everything directly inside GameAnimationSample using the animations that come with it, but that turned out to be quite inconvenient. There are some tutorials that show how to do this.
UE5 Game Animation Sample 12 - Aiming Down Sight

At first the idea was to assemble the animation setup and then build the weapon system afterward, but it quickly became clear that this alone could take more than a week. So I decided to try another project where most of the systems were already assembled and the effects were connected. Removing the effects and keeping only the animation took some time, because there were many dependencies tied to the main blueprint, which was a bit frustrating.

Discover over 50 free Niagara systems ready to use in Unreal Engine 5.7

In the end I wasn’t very happy with the animation itself or with how the character looked after retargeting. Retargeting was another thing I had to learn along the way. After that I thought about improving the animation and adding animation from one good free project.
How To Migrate And Use Animation Assets From Project Mega Sample
Download Almost 1,800 Unreal Engine 5 Assets FOR FREE!

Once everything was assembled, the result still didn’t look as smooth as expected. When the camera moved, the character and the animation started to jitter. It felt like I was still missing some understanding of how the system worked — there’s usually some checkbox somewhere that fixes everything.

After some more searching for a better way to add the animation I needed, I found a project that is publicly available and already built on an older version of Lyra from about three years ago. I tested it, but there were still a few things missing that I needed.
Updated Lyra Locomotion Project File (Free Download)- Unreal Engine 5.1

Essentially, what was required was a simple example based on Lyra animations that provided movement, aiming, shooting, and a weapon with projectiles similar to the standard first-person template — something simple enough that working on effects would not become unnecessarily complicated and with beautiful animation.

After some time I found a tutorial explaining how to import Lyra animations into a default project. With that knowledge, and knowledge that I got during week a better understanding of how animation blending works inside the animation blueprint , it became possible to use Lyra’s weapon animation layer to set up aiming and shooting, and then add the weapon system from the first-person template.
Lyra Clean to new project

[UnitFX]

I managed to get started this week and spent a couple of days troubleshooting an issue where, after hitting an object, it would eventually be removed from collision. I had to try a lot of things, but it turns out this is now a normal behavior after updating to version 5.7.
UE-358545 Unable to interact or collide with geometry collection after Removal on Sleep or Break timer finishes, yet unbroken piece continue to render
forums.unrealengine.com - 5.7

So, I simply took the projectile from the content example and used it as a base.
I’ve started with object destruction and haven’t added niagara (fragments) or smoke yet.

It’s certainly not fun, but it is what it is — this is how the collision situation currently looks. At one point I considered removing all the pieces and relying only on particle-based optimization, but the collision issues didn’t allow me to do that.

At one point I even managed to cheat a little: I made three levels of collision and deleted only the very last, third one, but there were still several pieces remaining in memory.

Oh yes, just in case, I made a backup and added an additional collision for impact in the blueprint to be on the safe side. This is a reliable option for this type of destruction I would say.

[UnitFX]

Added Niagara and the Niagara Data Channel to the Blueprint. There are large chunks of Niagara and many small sprites that create the bulk of the fragments.

[UnitFX]

I’m done working with the column, I guess. I might come back to it later when I improve its performance. And I would also like to add decals to the floor after everything disappears, it becomes very clean.

The next step will be adding impact. Then I plan to convert this room into an office and see how much performance I can save.

After the first stage, when I assembled the dataflow and added Niagara, I tinkered with the Blueprint and Niagara a bit more, which allowed me to improve the result a bit. I also liked a picture of a column I found online, so I decided to add some glass. I used a masked material for the glass; it looks cool. I noticed that ARC Raiders uses a masked material for the glass, and I was impressed with how it looked.

The first thing I wanted to update was the Blueprint. I was wondering how I could replace the legacy Write To Niagara Data Channel with the new one. Unfortunately, I didn’t dig deep and only found this option that worked.
I looked on forums and found that a lot of people were interested in how to do this. Luckily, a little later, I found official information from Epic, which was very encouraging.
new-access-contexts-in-unreal-engine-5-7

old one >

new one >

The next step I wanted to update was the ground impact. When the fragments fall, there’s no dust on the floor, but I really wanted some. I also wanted to add some dust on the sides of the column; it’s usually there when a large number of small objects fall after being destroyed.

So I first made a simple example on the GPU that, when a collision occurred, allowed the sprite sheet to be animated.


Here I later changed the size to more of a mix between fixed and length from the impact position to the floor.

This is what the result looks like with impact on the ground and dust on the sides of the column.

[UnitFX]

This week I was able to devote a few days to this project. I connected NDC to impacts and now I can customize weapon effects. I started with the impact; I wanted to do something interesting with a hit of electricity and energy.

This is the main impact, I also plan to add impacts from hitting different surfaces.

[UnitFX]

Small update, impact decal/muzzle/animation