By IAN FAILES
With so much going on in the real-time space right now, one way that companies have been both experimenting in real-time technologies and getting the word out about their developments is via bespoke demos.
Unity Technologies, for example, has made a number of short films to demonstrate their new real-time workflows. The most recent of these shorts is The Heretic, first unveiled at GDC 2019. It features a virtual human exploring some kind of underworld. For Unity’s team, the idea was to experiment with CG humans, procedural VFX and real-time rendering.
Since The Heretic’s first reveal, Unity has added a second component to the short, which was shown at the Unite Copenhagen 2019 event. In this add-on to the film, a new God-like character called Morgan comes into play. Morgan’s face and body morphs between different forms. Again, it provided a way that Unity could experiment with its latest game engine tools to produce the character.
Here the tool at play was the Visual Effect Graph, which can be used to build real-time VFX inside Unity. The Graph utilizes GPU run compute shaders and a node-based workflow to do so. The kinds of effects capable in the Visual Effects Graph could previously only really be done with Unity’s Particle System.
The Visual Effect Graph uses nodes and blocks in its operation. Calculations for particle simulations take place on the GPU (as opposed to the Particle System’s reliance on the CPU), and this means millions more particles can be simulated. The Graph is intended for effects such as environmentally-lit smoke, fluid simulations and detailed particle effects.
Morgan looks like a humanoid character, but is actually made up of constantly changing and undefined forms; it can be male or female and almost any size, with any changes to its form able to be made instantly.
Watch a session from Unity Copenhagen 2019 exploring real-time VFX workflows in The Heretic.
Essentially, Morgan is built out of particles, but importantly, these can all be adjusted in real-time, owing to the Visual Effect Graph. Every piece of Morgan is like a particle shard and controlled individually. Again, in real-time. “There’s no need to wait for simulations that I might have had to wait for years ago,” says Adrian Lazar, Lead Technical Artist at Unity.
Morgan’s morphing face and body seemed like a suitable opportunity to test out the Graph’s capabilities, says Lazar. “The alternative would have been to simulate everything in traditional software and then bring that back into Unity, which can’t then be changed in real-time. So we thought, let’s use this as an opportunity to try something new.”
The shape-shifting in Morgan is made possible in Unity via sliders, but even those sliders “actually drive a few hundred parameters behind the scenes to achieve the look,” explains Lazar. “You can expose just the parameters you want in the VFX Graph. I was able to encapsulate thousands of parameters that are behind the scenes into a few sliders so that whoever wants to play with it and then work on look development can do so more efficiently.”
Lazar adds that one of the benefits of having these complex particle simulations being done with sliders and in real-time is being able to instantly review character lookdev and shots. “It makes it possible to have live sessions with the creative director where you could share a screen, and pull the sliders around and change colors to find the right look for the character.”
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