Thank you very much for taking the time to review my art test submission! I made an addition to include the flame / explosion component. For the sake of security the navigation has been disabled and you may have to hit the back button to return. There are 3 pages Effect, Materials and Blueprints.
Below are links to Dropbox which may be higher quality than the embedded videos, also the images on this page have annotations when the mouse is hovered above. If you have any additional comments or questions feel free to contact me and I would be happy to go over anything.
Video 1
Effect with flames and fire.
Video 2
Effect without flames and fire.
Overview
For this art test, the effect was created in Unreal 5.3.2 using assets I generated in Houdini 20. I exported a combination of fluid / smoke simulations, geometry and texture sheets. These elements were then brought into blueprints to tie together the Niagara Systems, Chaos, materials and other components.
At the center of the effect is a dynamic remeshing Vertex Animation Texture (VAT) function that enables several components to playback fluid simulations. Layers of static geometry from other simulations cover the globs and tendrils, all controlled via Niagara. At the end are decals that are themselves small simulations, designed to erode in a way that makes them spread appropriately.
Niagara
There are 5 Niagara systems which include two for the fuse, an extensive goop system, and two used for pyrotechnics. The Goop system uses collision events to generate locations for secondary and tertiary effects. One of the interesting modules created for the main Goop's Niagara system is that it is able to detect if a surface is a wall or a ground and it filters either a wall decal that drips down and emits some droplets or a ground decal that is more radial with small VAT crown splashes. The check is on the hit vector and it's dot product similarity to a Z aligned up vector. Many of the smoke particles use motion vectors to eliminate the jittery frame blending used in the built-in Niagara sprite render.
Arrows show the alignment module doing it's work on the decals.
Goop Explosion.
Main fuse and the first effect to play.
Sputter that occurs at the end of the fuse.
Explosion fireball.
Flames System
Houdini
Houdini was use to generate around 20 different 3D meshes and alter / modify existing assets to enhance them with additional attributes. These assets are a variety of fluid simulations, the fuse and the exploding drum.
For 2D assets there are numerous decals for smoke, explosions and flame texture sheets.
Added a normalized gradient to the vertex alpha.
Thickness added to the barrel for fracturing.
Assorted goop particles for Niagara.
Tendrils Particle Mesh.
String that erodes away over time.
Main goop explosion.
Crown splash for impacts.
Smoke Simulation.
Flame Particle Mesh
VDB Flame Simulation
Textures
Smoke Texture Sheet.
Smoke Depth Sheet.
Decals were created using specialized fluid simulations and attribute tools to generate thickness and normals.
Vertex Animation Textures.
Flame Textures
Explosion Materials
Render Outputs
Textures used were rendered at 4K for the smoke and pyro and 2K for the decals, VATs are one pixel for each vertex by one pixel for the number of frames resulting in texture sizes close to 1024 x 24.
Decals were created in such a way that a smooth step dissolve creates a flowing animated appearance. Inside Houdini there was some manipulation to the colors and geometry to help shape the gradients.
Vertex ANimation Texture (VAT)
Please note that for this demonstration video below I used the auto play function and as a result the motion blur was not calculated using the manual controls that were in the actual effect. As a result the motion blur in this example video is exadurated and not representative of the final effect.
CHAOS
Barrel was fractured in UE5 after thickness was given to the mesh in Houdini.
Flame Mesh Particle
For this asset I made a flame than can hold up to being viewed from multiple angles so the over head shot works and the flames don't lay flat.
Performance considerations.
Some performance considerations are using mesh cutouts on Niagara systems, GPU particles for large simple sparks with separate CPU emitters for reduced number of accurate collisions. Using Niagara system controlled cycle time for all systems that do not need emitter cycle controls. Also removed most unused systems and modules. I utilized master materials with instances, lower mip on textures that need less resolution such as motion vectors, reused meshes and textures where possible. Blueprints operate on interfaces to optimize communications and updates.