Zeuxcg's 2016 Hackweek project

For all you who haven’t seen, Zeuxcg has been working on a lighting overhaul for Roblox.


This is going to go bigger than it already has, it’s likely going to go viral to everyone on here since it’s literally one of the best technical projects I’ve seen here. I decided I’d make a thread to talk about it, and potentially reach out to the technical director for questions.

This’ll truly make all projects shine, I really want this to come out but understand it probably won’t for awhile if it does.

To start off, I do have a couple “questions”. (The first one isn’t as important)

I wonder how much tweaking we’ll have to do to our current scenes if this is implemented. There are a lot of lighting “hacks” I and others I know use that may look our environments look pretty strange with this. But if we do have to tweak or rebuild things, it’d be so worth it. What are your thoughts on this? I know you mentioned in the demo that you didn’t touch a single thing before you implemented the new technology. If this truly will work in all circumstances that’d be fantastic.

You talked about GPU vs CPU stress at the beginning of the video when talking about your 2015 hackweek project, but if I recall you didn’t talk about it in regards to this new project. Will this switch Roblox’ graphics primarily from the CPU to the GPU, and make it so a lot of people that don’t have a powerful GPU won’t be able to run it as well? (Making it so a lot of people that can run Roblox well now … won’t be able to?) I’d love to hear your answer to this as well as any potential solutions you’ve been brainstorming on how to solve this problem - if it is one.

Again, the future truly is bright today. And I can’t stress enough how much I appreciate all the work Roblox staff, interns, and developers have put to push Roblox to greatness.


Guys Zeuxcg lied, this isn’t roblox, this is heavily edited footage from Unreal Engine.
(@zeuxcg, awesome project! )


I wonder if zeuxcg just went completely off the grid until we’re unhyped about his demo.


2015 all over again

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It looks great!

It should bring more realism to ROBLOX places and I really hope this becomes a feature in the near to mid future.

UE4 now feels bad now ahah!

Honestly I think its 9000% worth it, even if you have to modify your lighting related scripts to match this new version.
It looks so fantastic and will for sure improve the look of every single places, the textures also seems to have more depth, volumetric Particles… YAY !.
Also the light sources (points light etc…) are fixed (?) and no longer get through walls.

We have been waiting for this update for too long, I hope it’ll be soon.
I also hope that we’ll be able to try the “beta” on a gametest !


He’s done it again. Those changes are amazing.

I only hope that with these changes comes a way to prevent parts from casting shadows lest floating shadows ruin the immersion provided by the spectacular new shadows.

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Another massive bonus this should bring is that light shouldn’t leak through objects anymore :slight_smile:

Copying a reply from another thread:

Yes - there’s a lot of stuff to do to ship this, but the biggest question is the scope of the hardware this can work on. We’ll have to maintain the existing system for low-end mobile for sure, so will have to figure out content compatibility - that is, to adjust the old system to have a wider range of light intensities somehow etc.

On desktop as well I don’t know yet what hardware this can work on - as @TheNexusAvenger mentioned above I was doing all of this on mid-range laptop GPU (at 1080p), but the real question is what’s the min spec laptop that can run this (even if at a reduced quality); it’s possible some low-end systems on PC will have to fall back to the current system as well.

Re: content compatibility - it depends, really. There are some levels it works amazingly well at - I tried running Deathrun 3 with it and it looked great. Any levels where you don’t have much indoor lighting will just work as well. Now, some other levels won’t because I’ve seen light setup in some cases designed to sort of work with the limitations of the existing system - lights with very high brightness that never actually is seen to be that high, but makes the light “fill” the interior a bit better. It’s possible we’d have to get some tweaks to the light objects so that you can customize some stuff to accommodate, e.g. attributes that disable specular for a specific light source (and/or allow to alter its shape which seems useful anyway) etc.


If this dosn’t become a real update I am going to be very sad ):

Awesome project, I love the dynamics and realism of the shadows being admitted, reallyyyy hope this becomes a thing.


This is simply stunning. The things people could create with this kind of lighting would be incredible. I mean just think of some of the showcases like Life of an Otaku or horror games like Roses reworked with this lighting. Very exciting stuff.


I really wonder how well performance scales with varying amounts and varying distributions of lights that also cast shadows. Could it be somehow dynamically scaled back while still allowing shadow for all lights?

Looks super cool anyway!

My question might be answered in the video but I don’t remember.

How well does a light illuminate an area? I fill my indoor levels with lots of dim lights to give the level an even lighting spread because it seems to be the only way to do it. If you have bright point lights with a large radius then you have weird looking splotches of light spread around. If I do my current method with this system, would the lights all cast shadows and create a really weird looking environment?

I would ideally want a light to have a way better range as well as a better brightness falloff equation to allow one light to illuminate a large area. I’m sure this is not done for lag reasons though?

I ship it…

see what I did there


Yes - this is one of the issues we’ll have to solve wrt content compatibility. A variety of options is possible - better control over the shape of the light (e.g. block lights), varying attenuation, enabling shadows, being able to set up a specific light to only cast shadows from “grounded” (anchored/welded-to-anchored) objects so that the performance impact of shadows is minimal, etc.


absolutely extraordinary. I back it.

Already got this posted in feature requests, gotta love his work man.

Random irrelevant question:

How did you learn to do all this? This is A++ lighting and you literally made it in a week, it blows my mind. Please don’t leave roblox.


It’s not like he invented whole new pipelines and techniques for doing lighting, you always build on top of existing work / algorithms / frameworks.

Also he’s been working as a senior (rendering) engineer for a long while now so it’s to be expected he knows a thing or two about graphics. :slight_smile:

Still impressive AF that he did almost all of this in 4 days. (He says on his twitter he finished a day early… wtf)