Physics Performance Demo: Domino Stress Test

By Kevin He - March 20, 2013

As you may recall, we recently published an in-depth article about how we’ve sped up ROBLOX’s physics by 2-4x as a result of modeling collisions using impulses rather than springs. The “impulse solver,” together with three recent bug fixes, has drastically improved the performance and realism of one of our favorite physics-engine stress tests: Ultimate Dominoes! by armitroner. In this test, a single force cascades through thousands of standing parts, causing them to topple in quick succession.

Impulse Solver Gives ROBLOX’s Physics a Serious Speed Boost

By Kevin He - February 23, 2013

In late 2012, a significant fraction of ROBLOX developers worked together to make games run on performance-constrained hardware (iPad, iPhone and iPod touch, to be exact). The team set off on an exhaustive hunt for inefficient processes within the ROBLOX source code, then found ways to optimize the problem areas that had substantial performance payoffs. This allowed us to bring the full in-game multiplayer ROBLOX experience to mobile devices in December, but we did have to make a concession: there would not be a destructible environment in ROBLOX Battle. The physics simulation was too resource intensive.

Soon, that’s going to change, as Kevin He has altered the way ROBLOX handles collisions – one of the major components of our distributed physics engine. Better yet, you’re about to see a 2-4x increase in physics performance across all games and hardware.

Smoothing ROBLOX Character and Vehicle Motion

By Kevin He - October 27, 2012

When you see ROBLOX characters moving in-game, their motion occasionally appears to “stutter.” The problem is magnified in certain scenarios; for example, two characters standing in close proximity on a moving conveyor will appear to stutter dramatically in each other’s camera. ROBLOX Client Physics and Networking Lead Kevin He recently dove deep into this problem, as it applies to characters and vehicles, and has some observable improvements to share.

First off, let’s take a look at some before-and-after video. In both clips, there are three players in a vehicle and the video is captured from the camera of a non-driver passenger. On the “new” side, it’s clear that much of the vehicle’s motion stuttering has been eliminated.

Enhanced Water Physics, Vehicle Seats Support Rear Propellers

By Kevin He - September 25, 2012

We’ve talked previously about our ongoing effort to build robust joints and motors, and even touched on implementing seats for boats that support rear propellers. We’re still ironing out bugs with our soon-to-be released robust joints and motors, but we decided to release our new boat seat and water propeller support first. These features function independently, letting you experiment with propellers and watercraft today. Though this blog post features some pretty complex ideas in terms of building, we are hard at work on streamlining these building methods in the future so they’re intuitive for all uses. For now, check out what we’ve got so far.

Spotlight: Mechs, Motors and More With TakeoverTom

By Alan Fackler - September 12, 2012

It’s rare that we have the opportunity to spotlight a user who lives in our immediate area. So we jumped at the opportunity to meet TakeoverTom, who lives only minutes from our offices in San Mateo, CA. He swung by our offices with a green box in tow. This was inside.

Robust Joints and Motors: Keys to Better Vehicles in ROBLOX

By Kevin He - July 27, 2012

At ROBLOX Game Conference 2012, Kevin He dissected the steps he’s taken to refine ROBLOX’s water physics, hinges and motors so that vehicles – especially boats – perform more realistically. In this blog post, we’re recapping the key parts of the development process. You might be surprised at how much work goes into physically simulating real-world machines in a life-like fashion.

ROBLOX’s water, released in June, gives you the ability to create a boat that floats based on actual physical properties, rather than lines of Lua code. While the release of water marked a big step forward for ROBLOX, it has its limits; for example, if you want to create a propeller-powered boat, the propellers have to be on the side of the boat, as though they’re mimicking wheels on a car.

We’re working toward releasing a vehicle seat that gives players greater boat control, namely over rear-facing propellers that function based on real physical forces. It sounds simple, but it’s actually the culmination of two complex physics engine developments.

Testing the Accuracy of ROBLOX Physics with Potato Cannons

By Sorcus - June 7, 2012

ROBLOX is built on a comprehensive physics engine, and our developers are constantly optimizing it so it can handle interactions between more physics objects and players, in an increasingly accurate and consistent way. We recently put our engine to the test with a new projectile-motion simulator – and most satisfying armament – the ROBLOX Potato Cannon. According to the results, which we describe in this article, we’re on the right trajectory.