Creating Exploding Dark Liquid Effect in Unreal Engine 5

Introduction

I'm Daryll Española. I've been working with Secret 6 Inc. and the game industry for about 7 years. I started as a game programmer, then eventually shifted to real-time VFX. I was assigned to an original IP called Project Xandata, where I worked extensively on the VFX. That's where I first started in the specialization and self-studied the craft.

After it was released, we pursued providing VFX outsourcing services while I became a Lead VFX Artist. It has now grown to over 10 VFX artists between Manila and Madrid. I have since worked on titles such as MediEvil, and The Lords of The Fallen. At the same time, I’ve been working with an indie game company Astral Clocktower on their game called Kristala. 

Unreal Engine 

Since I was in college, Unreal Engine has been my main game engine. I remember starting with an early version of UE4. Today, UE5 is incredibly powerful to use. All these new features like Lumen, Niagara, and improved material system boosted the visual look and benefitted real-time VFX artists. Personally, I liked the Cascade system as a Particle System Editor, it is simple and super fast. But the new Niagara system has a more versatile system that unlocks endless possibilities, and it is overall easier to manage (thanks to its improved UI/UX and powerful optimization system).

The Dark Liquid Burst Project

The Dark Liquid Burst project was initially my study project for a liquid-like FX such as blood and... other gooey stuff. Creating liquid VFX is one of my weaknesses, as it’s hard to mimic especially because of its organic shapes, shading, and animation. At the same time, I received a lot of projects that dealt with blood and liquid. I was inspired by the oil FX from Death Stranding and a great movie called There Will Be Blood.

First, setting up a test level is a must. Make sure that the lighting is good enough to complement your VFX. You can start on a neutral lighting setup (not too warm or too cold) with just the right amount of exposure (not too bright or not too dark). I tend to use clean grayish backgrounds to prioritize the look of the VFX above anything. 

I use the Level Sequencer to simulate Niagara. With VFX art, you have to be able to test it over and over again in a very efficient way. Especially for the one-shot burst effect, it would save you a lot of time on iterations. The most complicated part for me is creating the liquid-like shading, with textures that dissolve smoothly and retain the shape that mimics the organic liquid behavior. To create the texture, I used Photoshop for the alpha mask and went through a lot of trial and error before ending up with a few shapes that I liked. 

The dissolving part is tested mainly with the level adjustment. I have to adjust the black-and-white values to dissolve the texture smoothly, and to make sure it has a good amount of details when it lingers. After I created the alpha mask, I then bring it over to Substance 3D Designer and use the alpha mask to sample a normal map. 

For the material setup, there are 3 important recipes for creating liquid-like shading:

1. Fake specular sampled from the normal map
2. Dissolve function
3. Color modifiers (Fake Specular Tint, Color Lerp, and Exposure Controls)

I then test the materials in Niagara and animate them using velocity and acceleration. I use Dynamic Parameter with a float curve to drive the Dissolve. There is no custom formula in terms of technicality, it’s just a matter of applying the VFX principles. Movement and shapes are very important factors. 

Explosions

There are three separate assets that I created and combined in a single blueprint actor. The first is the actual explosion, which is a Niagara asset and consists of a spherical burst behavior. In this explosion, I layered four emitters, one with a shape that could form a distinct organic silhouette when populated. Two is a thicker layer to add volume to the effect. Third, small liquid drops, and lastly, burst smoke for the micro details. 

The second layer is the decal, I use the deferred decal actor as a component. It is rotated randomly to have some variations – it’s much better if you can randomize four sets of textures. 

The third layer is the splatter, which I intended to set up as a separate Niagara asset so I can repurpose it. The effect has two emitters. One is the source emitter that generates a collision event. Second is the splatter sprite which receives the collision event and spawns at the source location. It has an added material formula to function like a decal projection. I initially wanted to use the new Niagara component renderer which unlocks the possibility to spawn decal components directly using Niagara, but it turns out that it does not work on event handlers that receive location. Perhaps creating a custom location formula could solve it. 

Tips for Beginners

I think the best thing to start is learning the engine’s particle system (Cascade, Niagara, and Shuriken) and other technical things such as creating shaders. You actually just need to master one since they all work very similarly and it’s much easier to switch by the time you generally know how it works. I can recommend this really good intro tutorial series for Cascade System created by Epic Games.

Once you get familiar with navigating the technicals of these tools, you can proceed on learning the VFX principles: shape, timing, color, and values. These are the most important aspects when creating a VFX. It is likely the very foundation that you’ll often use in your career even outside of real-time VFX such as for films and motion graphics. It is hard to master and definitely takes a lot of time to be good at it. I really recommend this VFX style guide from League of Legends. It is one the best real-time VFX style guides and is an example of where the VFX principles are used and are well executed.

What’s great about creating VFX is that there are a lot of tools that you can experiment with to create really cool stuff. Adobe Photoshop and a game engine would be enough when creating a great effect. When you get advanced and want to learn more about these sorceries, I highly suggest learning these tools:

• Embergen (for simulating smoke, fumes, and explosions),
  
• Substance 3D Designer (for creating noise, flares, and generating organic textures),
  
• Houdini for procedural 3D and baked animations.
  

To add more specific resources:

• Boris FX for generating lightning strands textures.
  
• Vector Ray Gen for creating vector fields.

Lastly, consume a lot of VFX references and media. This will train your eye to break down VFX layers and be better at deciding how an effect should be made. I’m looking forward to seeing the VFX community grow!

Daryll Española, VFX Artist

Interview conducted by Theodore McKenzie