How Landfall Games finds the fun in physics engines

Landfall Games have made a name for themselves over the last few years for wonky physics-based games like Clustertruck, Stick Fight: The Game, and Totally Accurate Battle Simulator.

What began out of necessity due to their lack of an animator, has since become their calling card in the industry – namely making games using physics animation over the more time-consuming method of keyframing.

With that reputation, however, has come a difficult challenge. Every new project requires the studio to make a new physics-based control scheme which feels just as fun and responsive as the last, while also giving room for a certain degree of silliness and emergent humor. It’s a tricky balancing act to get right, but one that they seem to have mastered internally.

According to Petter Henriksson, the co-owner and COO of Landfall Games, the studio has achieved this through a bunch of different approaches. These include constantly reiterating and fine-tuning their games over time in Unity, creating a framework that allows for new ideas to be implemented quickly and efficiently, and communicating their intentions clearly to their audience.

How it all works

You can see the first of these approaches across nearly all of their projects. Though Totally Accurate Battle Simulator is probably the best example of this. It's a physics-based tactics game where players place a bunch of humanoid units on a map and do battle against an army with increasingly ridiculous weapons.

Originally conceived at a game jam, it has since grown significantly with new unit types and a constantly evolving physics system. In the game, you don’t directly control the units. Instead, you simply place them and how they act is based on a number of different systems. To accomplish this, the team adds torque to the ragdoll’s legs based on animation curves to create a basic walk cycle, before enabling a number of additional scripts to help with animation.

These include a step handler to determine when a step has been completed and when a new one can start and a standing handler that is in charge of keeping the character upright. The latter of these judges the distance between the character’s head and the floor, and then exerts an upwards force on the character’s torso and head if they are able to stand. This is based on an animation curve where X is the distance to the ground Y is the output force.

Then there’s the balance script.

“The balance script adds force to the legs and feet to try to keep them in position to help support the body,” says Wilhelm Nylund, game designer and CEO at Landfall Games. “For example, if both feet are in front of the bodies center of mass one of them needs to move backwards so that the character can stay balanced.”

The importance of iteration

This physics animation system is the third iteration of the animation system and makes workflow much quicker and easier to handle.

“The biggest changes in the physics animation system is that I've made the new one a lot more component based,” explains Nylund. “In the old system there was a script called PhysicsAnimation.cs which handled keeping the character upright, checking if there is ground underneath, rotating legs for the walk cycle, etc. In the new system each of these are their own scripts that you can pick and choose from.”

The new approach is similar to how they handled the animation on another one of their games, Stick Fight: The Game. Iterating on their tools has allowed them to simply tweak the movement of different unit types. For example, the snakes in the game are using the exact same movement, gravity and rotation handler as the humanoids, but don’t have a standing handler as they have no legs. This would have been a more involved process without the scripting system in place.

Prototyping and workshopping ideas

The ability to prototype and incorporate new ideas quickly helps them to create a fun and chaotic experience. Another way they accomplish this is through the use of a singular humanoid across multiple unit types.

“They are all running on the same code,” Henriksson explains, indicating towards the human units in the initial trailer. “They’re just told to hold an object. Then something triggers when they go into an attack state and that differs depending on if they’re shield men or an archer or something, right?”

This efficient method of development has led to some bizarre, new units making their way into the game, including mock versions of Donald Trump and Hillary Clinton, and a man that farts chickens.

“Everything we do is kind of random,” continues Henriksson. “We actually thought of one of the units mid-meeting in China somewhere. Like what if we make like a business dude that has like a portfolio and he like grabs you with a hand and then starts punching you with a portfolio. It’s things like that. But then Will is most likely the one who comes home and puts everything together.”

New game, new perspective

With a physics system already in place for Totally Accurate Battle Simulator, you’d be forgiven for thinking that Totally Accurate Battlegrounds, Landfall Games’ PlayerUnknown's Battlegrounds parody, was an easy task then. Simply take the animations and code in place and build the new game around that. However, you’d be wrong.

Creating a physics-based first-person shooter was a surprisingly difficult task that required a complete rethinking of the physics present in Totally Accurate Battle Simulator.

This was due to the demands of the genre in terms of its first-person perspective and the studio’s strictly physics-based approach. If they were to use the code running the units in Totally Accurate Battle Simulator, it would be unplayable. The player would be unable to view what was ahead of them clearly, with the world bouncing around and spinning wildly ahead of them.

“In other games, you would probably have first-person animations and then you would have third-person animations when you look at someone,” explains Henriksson. “But in Totally Accurate Battlegrounds, it is the same. Your first-person animation is also what everyone else sees.” This meant something had to change.

Letting your audience know your intentions

Nylund had to build a whole new physics animation system that would work across both a third and first-person perspective, while still utilizing the script system he had developed across other games.

Of course, the result isn’t as clean as your typical first-person shooters, but that is kind of the point, with the head bobbing and goofy movement lending the game that familiar charm that many have come to expect from the studio.

“The wonky part is kind of cool because if everyone doesn’t take the game so seriously we can have a lot more fun with it and do more things like we have a gazillion weapons in Totally Accurate Battlegrounds and the reason we can have that is that every single one of them doesn’t need to be balanced and thought out,” argues Henriksson. “We can just add a bunch of cool ideas into weapons and just have them in the game.”

To close the interview, I ask Henriksson what the future holds for Landfall Games. What are they working on now, and are they finally going to hire an animator or continue making physics-based games.  

“For now, we are definitely just going to figure out how deep we can go with physics animations,” answers Henriksson.

“At the moment, we’re doing Totally Accurate Battle Simulator and Totally Accurate Battlegrounds. The plan is to keep doing Totally Accurate Battlegrounds until the servers are pretty stable and people can play and there are no big issues, and to continue and finish Totally Accurate Battle Simulator," he concludes. "We’re [getting] there.”