WARNING: this video contains footage of Half-Life Alyx.
Rather unsurprisingly, since its release, Half-Life Alyx has continued to get updates.
Up until now it’s been about fixing bugs and adding accessibility options, but today’s
V1.4 adds liquid in bottles! Matthew Wilde, visual effects developer at
Valve, tweeted about it claiming that this ‘booze shader’ had been his lockdown hobby
and that it required ‘lots of research’. Yeah sure. Though saying that, it probably
did. Because the result is awesome. And when I say that, I mean it’s on par
with messing with the physics in Half-Life 2 for the first time, or the trees in Crysis.
It’s the sort of cool new tech that’s so cool, you don’t care how stupid it makes
you look. I proudly admit to spending a large part of today, slavic squatting, hunched over,
mouth open, staring at virtual bottles with the fascination of monkey. It’s just such
a cool feature, and the effect holds up regardless of the angle, or how close you get to it.
I don’t THINK the interiors of these bottles are physically rendered- what you’re seeing
here is some kind of shader-based illusion applied to the outside of the bottle. It’s
hard to know for sure because the effect looks too good for that. But you can see here this
kind of bottle ends at the bottom of the neck, and shoving my head through this bottle full
of liquid, it seems empty on the inside. So, given these limitations, this booze shader
looks better than it has any right to. It isn’t just about getting the physics
right, but also the bubbles, the refraction and the shine. And it gets them all perfect,
setting an impossible bar for other games to follow.
Being the shape these bottles are, I couldn’t ruin the effect by getting liquid to pass
through solid surfaces. Liquid doesn’t magically pass through the neck- though I wonder if
that’s because they’re all strategically half-filled or more. Further testing is required.
Starting from the beginning of the game, it quickly becomes apparent that not all bottles
contain liquid. There was one but I messed that up. But when you think about it, it makes
sense that most are empty- who would leave a full drink lying around? Sometimes you do
get lucky, but 9 times out of time it’s piss. In-game, it wasn’t until I reached
this place that I found some full bottles. Who would leave so much booze unattended like
this? It’s just asking for some weirdo to come along and to start analysing the physics.
So you have varying amounts of liquid, in various colours. But they also contain different
levels of bubbliness. The best is this one here. Shake it hard enough and the whole thing
gets filled with foam, which gradually settles until it returns to its usual liquid, slightly
bubbly self. It looks like foam, it looks like an ocean of bubbles racing to the surface.
It’s hard to get a good enough look at the effect to spot the flaws, since the bottle
itself masks the liquid with its coating of dirt, scratches and stickers.
I don’t know if this was intentional, but the stronger stuff has that slightly greasy
look to the bubbles, much like real alcohol does. It’s a super authentic effect and
the bubbles and surface hold up from every conceivable angle.
They refract the background, and you’re just going to have to take my word for this,
but viewed in 3D it appears even more convincing. In some places it didn’t feel like it was
lit brightly enough by the sun passing through it. But get it just right, like in this sunny
spot here, and it looks marvellous. Shadows of stuff cast across the bottle. Which itself
is mightily impressive. Though it didn’t react to me passing an object in front of
it like this. And the shadow’s a bit grainy. Terrible.
I booted up a… fan-made map with changeable gravity, and this was where the effect fell
apart. When the gravity changes, it doesn’t smoothly transition. It jumps between them
and a glass half empty suddenly becomes half full. I guess, once that transition’s happened
and the gravity’s reversed, it’s equally authentic upside down, but my brain can’t
process where the liquid and bubbles are supposed to be or which way they’re trying to travel,
since I guess I’ve never encountered something like this in real life.
Disable gravity and the whole thing panics and doesn’t know what to do with itself.
But I can’t blame it since I’d probably do the same.
I did try analysing it more, but the gravity went horribly wrong and I started having to
fight against every-day house-hold furniture.
Valve, pls fix.
So yeah, a lot of fun to mess with. I’ll end with a few more clips for those of you
who are interested.
These large water containers are the worst example of the water shader. Perhaps they’re
just too big to get away with the limitations of the effect, as it seems more like a thick
gas than a liquid. I just couldn’t get a good look at it no matter how hard I tried.
Sometimes, marks from one side of the container seemed to project across onto the other, which
was cool. Unless it was just a buggy shadow. In which case, it isn’t. But the water itself
isn’t worth mentioning, and shooting it doesn’t cause it to leak. Let’s get back
to the pretty examples again.
Having had a very similar bottle before, I can vouch for this one’s authenticity.
There isn’t another game that comes close to this level of detail just yet.
And lastly, a long clip showing me shaking up a bottle and then waiting for it to settle
again. Well done Matthew, your lockdown was well-spent.