Hey! I’m Tobias Ahlgren, a VFX artist from Stockholm, Sweden. I’ve been working at DICE since late 2016, shipping games like Star Wars Battlefront II and Battlefield V. I came to DICE fresh out of five years of school, doing my Bachelor in Computer- and Systems Sciences at Stockholm University and then following that up with another two years of Game Art at the school FutureGames.
Cosmic Trail VFX: Start of the Project
DICE is an awesome workplace for many reasons and it just so happens that two of those reasons wound up setting the stage for me to create this effect which I’ll break down for you today. It all started with the DICE Mentorship program, where my awesome colleague and fellow Futuregames alumnus Erik Öhman and I got in contact with the current VFX students at our old school. Going through their concepts and ideas I got introduced to the work of Sarah Carmody. The combination of Sarah being really talented and the fact that it’s not that common to see animated concept pictures for VFX made her work really stick with me, so when the next DICE Hack Days came around I saw my chance to try it out for myself. I believe Sarah uses a different workflow and software using flow maps, but I decided to keep it simple for my first attempt only using Photoshop and After Effects.
I didn’t really start out with any initial references. Instead of looking for an inspiring image that I could reproduce as close as possible, I wanted to make something that suited the technique I was attempting to follow. As such my Photoshop process was pretty simple. I just started out trying to get a rough shape that I liked, and then adding details little by little as it became more clearly defined. I used a rough brush, lots of smudge tool and gradient overlays to quickly try different color schemes.
Animating the Concept
At this point I wasn’t really thinking about implementing the effect in the engine, I primarily wanted something that I could try animating in After Effects. Moving over to AE where I’m not as experienced was a great learning exercise. I started off by using some fractal noise as a displacement map for the concept picture. This is an easy way to get some subtle secondary movement, but it mostly jiggles back and forth, lacking a clear sense of direction. I then added a layer of panning stars, going from left to right, on top of the displaced image to give the concept a defined direction, which in turn helps to trick the eye into believing the displacement map is also going in the same direction. If I had more time I would’ve wanted to add even more layers of movement and offset their timing in order to make the entire composition loop more seamlessly.
If you wanted to make the entire concept flow from left to right you could keep the head of the projectile stable and animate the trail from left to right. You’d have to apply a static opacity mask in the center to keep the trail from just going off-screen as you pan it to the right. Apart from this you also have to make sure the concept tiles from side to side, so you can recycle it when it goes outside of the mask, otherwise, you may have trouble looping the entire composition when you’re finished.
The great thing is that these techniques are very similar to the ones used for making shaders, which I’ll talk more about when discussing the in-game effect.
If you want a more detailed tutorial on how to use fractal noise and displacement maps to distort footage you can check out this awesome step-by-step tutorial by Justin Odisho.
Upgrading the Effect
Once I finished the concept, the color scheme reminded me of the Pokémon Suicune which in turn led me to go for a smoother and more flowing motion in the effect compared to the slower movement of the concept. This difference in animation speed gives a drastically different sense of scale, turning the effect from a massive shooting star into more of a magic projectile.
If you compare the two final GIFs you can see how the 2D version is just distorting and not actually moving apart from a few tiny stars. Moving on to the in-game implementation I wanted to get a more flowing sense of motion and this meant I couldn’t just distort a single image and add a layer of panning detail on top as I did for the concept. Instead, I had to make the texture of the trail tile so it loops when it’s panned over a mesh and add UV-distortion on top of that. Because of these new requirements, I started off by making new textures in Photoshop. I masked out the head of the projectile to keep the core stable and started by panning the trail.
Depending on what the gameplay demands of your effect, the mesh used for the projectile will vary. As I didn’t have any restrictions, I decided for simplicity’s sake, to make the mesh a bent plane. This works well for top-down cameras used in games like MOBAs, ARPGs or RTSs, but would not hold up if the projectile could be viewed from any angle.
Then I added another layer of movement with two spinning spiral meshes with a similar shader applied to them and finally, I created some stardust using GPU particles and small ribbon-trails for some micro detail. With the core trail just being a static mesh, this solution works well for projectiles that move in a straight line, but for homing projectiles, you would need to have a different approach using a ribbon or mesh trail solution with a similar shader.
Cutting a few corners due to the time constraints of the DICE Hack Days made this a really cheap effect in terms of both time and performance. All in all, it’s a pretty simple effect, using essential shader techniques and mixing sprites, ribbons, and meshes. This makes recreating it a perfect exercise for a VFX artist regardless of their level of experience.
I find working with loose constraints and letting your creativity and inspiration decide the outcome really rewarding. When working on a game your effects always have to serve a purpose, be it communicating gameplay or making the environment more immersive, but there will almost always be some room for innovation and creativity as well. Especially if you are an aspiring artist looking to learn new things and improve your portfolio, try letting your imagination take the lead. It will help you stay motivated and make your art speak for itself. There’s nothing more discouraging than going down the rabbit hole with an idea or technique that just drains your time and energy.
- After Effects
Getting into VFX
I highly recommend anyone looking for a way to get into games to check out VFX and see if it’s something for you. VFX artists are not only a rare breed and greatly sought after in the games industry, but VFX is also (subjectively) the most fun and rewarding discipline as you get to dabble in all kinds of other disciplines and software. Since VFX is such a broad discipline, there are many different areas in which one can deep dive into. While this is part of the appeal, it can also make it seem daunting from the outside. There are many different game engines out there with their own proprietary tools, and with new additions like the VFX Graph for Unity and Niagara for Unreal, some engines have so many tools it can be hard to understand their different purposes and functions and know which one to learn first. If you’re looking to get into VFX without any previous knowledge whatsoever I recommend checking out Epic Games Introduction to Cascade playlist. While Unreal Engine may have been updated greatly since the making of those videos, the basics that they cover, - for example, effect setup and emitters, - all still apply today. Cascade and other stack-based systems like Unity’s Shuriken are the most commonly used tools when making effects for games so learning them will get you far.
Another great resource that has stood the test of time is Julian Love's GDC Talk on The VFX of Diablo, where he talks about principles that apply to all levels of experience. He also gives a basic overview of texture multiplication in shaders, which is the same technique I used as the cornerstone of my cosmic trail effect in this article. Making shaders is very common for a VFX artist, though it doesn’t necessarily have to be very complicated. Choose your technique based on your skill set and what you find interesting, as there are often multiple solutions for the same problem. My cosmic trail is mainly built with shaders on meshes, but if you’re not comfortable with shaders it could also be reproduced with sprites that change color over their lifetime for example.
As a VFX artist, you’ll find that basically every other aspect of game development is an area worth exploring or researching to further improve your effects and workflow. There’s always something for everyone, be it simulations in Houdini, scripting/coding, textures in Photoshop or Substance, lighting, modeling, animating, and/or rigging in Maya only to name a few.
For further reading, tips & tricks, awesome inspiring VFX work in the monthly sketch contests, and more, head over to https://realtimevfx.com/ and their Discord. For more of my work, you can check me out on Artstation!