Page 41 - 3D World - October 2017

Feature
Creating game worlds

structures, you can activate that
building’s unique function.
Initially, buildings could change
states to support the Wild/Tame
game-play mechanic, but with the
benefits of VR it became apparent
that the experience could be
enhanced by pushing depth in
other ways.

10 VoxElisAtion ProcEss
Ian Moran, technical
director at the Secret Sorcery,
explains how he captured scene
assets so that they materialised in
front of the player.
“We have multiple states for
objects and environment, initially
we had buildings that morph from 11
one state to another, something
that looked great when the
player was closely observing the
transition, but in VR, large-scale
effects are what catch viewers’
attention. We wanted an effect that
was much more spectacular and
far less subtle, so we thought ‘What
if we were able to move objects into
the domain of particle systems?’ –
then we could form objects particle
by particle and have objects 12a
exploding into dust.
“For this we engineered a
process that would capture
polygonal and sculpted models into
a point cloud in a way that’s similar
to a 3D laser-scanned real world
object. We could even choose the
number of particles/voxels, which
would allow for levels of detail and
performance to be rationalised too.
“Models were ‘scanned’ from 12b 13
several cameras using the results
of a deferred buffer capture. With tools are essential to ensure your through water flowing over it Unreal uses nodes
this we could fuse a positional scene is as efficient as it can be, was initially implemented using for many tasks,
point cloud with colour and normal checking for areas of complex screen-space techniques. This which makes for
data enough to suitably represent overdraw and so on. looked impressive, but it actually an adaptable and
an object. Point cloud was then Performance in VR is a suffered from artefacts that broke powerful workflow.
rendered using a custom shader requirement rather than a flexible immersion in VR.
that would form at each point along ambition, to hit target framerates is “By using a simple parallax-
mathematically calculated paths. paramount. The statistical reports like shader technique to address
“With additional voxels joining make this something that artists the riverbed texture, this didn’t
with pre-existing buildings as can tune their work to directly, require direct sampling of the
performance allowed, voxels rather than leaving content to be scene and didn’t have the artefacts.
overlay the existing structure culled by programmers. This created significantly higher
for a dramatic result. Buildings performance, which is always
could then form from thousands 12 Vr-FriEnDly wAtEr welcome for a VR title.”
of particles, falling in patterned, Ian explains how the water
mathematically defined paths from was approached for Tethered. 13 PlAying with
the sky.” “With welcomed additional PArAllAx
performance courtesy of With the archipelago of floating
11 wAstE not, wAnt not PlayStation4 Pro, we could develop islands surrounding the player,
In the land of VR, refractive and reflective water. much time was spent structuring
optimisation is key, and profiling The refraction of the riverbed their rhythmic formations.

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