Sims 4 – Animations and Multitasking

Marion Gothier (SimGuruMarion) showed us the last Master Class at SimsCamp: Animations and Multitasking.

As everything else, the stuff shown is still in an early state and many things can change. Everything that was shown to us does work in the game at the moment although Marion only showed pre-recorded videos from within the game.

Sims 4 Sims should be less robotic and a lot more human. That lead to the identification of four major aspects in animations: More natural animations, better routing, better social interactions in groups and multitasking.

Natural Animation

As you can see in the gameplay trailer, Sims do move a lot more natural. They don’t walk in one direction, pause, turn and then walk in another direction. In Sims 4 the movements are smoother. If Sims want to go in a different direction, they start turning while they walk. This can be pointed out in the way Sims sit down.

This is how it was in Sims 3: The Sim walks up to a chair, pauses, turns around, pauses again, and then sits down. In Sims 4 it’s like this: The Sim walks up to a chair, turns while still walking, and sits down in the chair. No pausing.

Sims 4 can now move around rooms freely. They can turn 360° and walk in any direction they want. This enables them to maneuver in tight spaces and rooms without issues. More info about this can be found in the part about routing.

Another issue that Maxis tried to improve is that Sims should be able to do all animations in almost all places (where they make sense of course). An example is that a Sim can tell a story either when sitting down or standing up. It both works. Sims can now sit wherever they want and everything they can do sitting on one type of chair, they can also do on another. Because of this, they can now sit on a bed and eat if there’s no free chair available.

Sims that talk to each other now not only turn their heads but their whole upper body which really makes the Sims appear involved in a conversation. If a Sim passes by another Sim it can also happen that he turns to acknowledge that the other Sim is there. They are now aware of each other.

Facial expressions are very important in Sims 4. So the mouth moves as well, even if not perfectly synchronized with what Sims say. The costs for that would be to great. This leads to recycling of different lip movements for different speaking parts. It’s not perfect, but good enough.


Don’t we love our Sims 3 Sims when they stand around cause another Sim or object blocks them ? When they wave and moan cause there isn’t any room ? They get stuck and can’t use whole areas cause they are taken up by a oval (aka SocialJigs) ? Resetsim has become our best friend.

If everything goes according to plan, these problems will be a thing of the past. Sims should not get stuck anymore and routing should not fail just because someone is standing in their way.

Marion shows us a few impressive examples how that all works in Sims 4:

  • About 20 Sims stand in a circle and all walk towards the middle. It soon gets very crowded and our Sims 3 Sims would now start foot tapping and waving. Not Sims 4 Sims. They maneuver past each other quite elegantly
  • A group of Sims tries to fit through a door. Ah, that will take forever, right ? No wrong. They can walk through the door almost simultaneously.
  • A group of Sims is having a conversation in a tight house entrance and another Sim wants to get past them to sit on the sofa in the living room. You can imagine how that would work in Sims 3. This again works without a hitch in Sims 4. The Sims even turn to the group when passing by and then find their spot on the Sofa.

Another new feature is that if you place a curved path on your lot, the Sims will actually follow that and not walk on the grass. There is a limit to this though. If you build a spiral, they won’t follow that.

Social (Group-) Interactions

Interaction in groups is an important part of Sims 4. Maxis did a study of ‘human behavior in the wild’ for that. They filmed a party and studied how everyone acted and then tried to port that to the game. As already mentioned, Sims turn to each other when communicating thus showing a different level of attention than before. Sims react more to what other Sims do and don’t just stand around. They are actually have a group conversation.

Sims can now even talk if one is sitting and the other is standing. No need to find that one special place somewhere outside near the bushes where there’s enough room to talk to each other.

At the moment, Sims can form groups of up to five to six Sims to interact with each other but that is not a final number. After this, the game tries to break the groups up. This would work similar in real life since groups that are too big won’t work there either.

A interesting point that was studied was how people socialize and behave when talking to each other in groups. We humans have a tendency to keep a round circle. This means that if someone is leaving a group or joins in, we take a step aside to make room or close free space. Maxis has tried to do the same with the Sims and so they now move aside and close circles for them to become round again. Contrary to the Sims 3 this doesn’t seem unnatural but happens subconsciously and the conversation continues while this happens.


Multitasking is another big feature in Sims 4. But what does multitasking mean ? Can my Sims now walk hand in hand down the street, talking to each other ? Can they cook and talk to other Sims at the same time ? Can they even interrupt something, do something completely different and then come back to it ?

Not all of these questions were answered but many tasks can now be done simultaneously.

photo by EA

As an example we are shown a Sim on the treadmill as they talk to another Sim and works out at the same time.

The example starts with them having a conversation (no treadmill). Now one Sim is sent to the treadmill. The other remains where they are and keep talking to the Sim that wants to do the workout. On the treadmill, that Sims starts answering and keeps working out while they keep running.

The speech animation was not programmed to work on the treadmill. It is simply superimposed over the running animation. Each animation knows what other animations it is compatible with.

A second example was at a party. Sims can now eat and drink while standing around and talk to other Sims. If they want to eat the glass disappears from their hand so they can hold the fork to eat. After the Eating-Animation is done, the glass reappears in their hand. If there is a table, the objects don’t disappear. The Sims put them on the table.

Some things can be done at the same time, for others one is interrupted and Sims go back to them after they finished the interrupting animation. As in real life, not everything is compatible.

While cooking Sims can now also talk to other Sims. They won’t stir the pot and talk at the same time though. As in the other example they will stop stirring to talk to the other Sim and then go back to cooking. They continue to cook while the other Sim is talking to them though.

This brings up the question what influence this will have on the interaction queue. Well, each interaction has a representation in the queue and compatible ones will be done together. You can cancel any interaction separately. It wasn’t shown to us, how this works in detail.

The question if a Sim can now walk and talk at the same time was not answered and also not the question if Sims keep standing next to a oven until it’s done or if they can do something else while the meal is cooking.


How do emotions influence animations? Will there be a special animation for each emotion depending on whether the Sim is sad or angry ? No, that would not be doable. Marion told us a few numbers: Sims 2 had 12’000 animations, Sims 3 10’000 to 11’000. So if there are 15 emotions that will be just over the top.

The solution chosen is to concentrate on a few key animations that Sims do a lot, like the walk styles or certain interactions that are only possible if the sims have a certain emotion (see Sims 4 – Emotions for that). On top of that there are some signature animations that show the player in what emotion Sims are currently in.

On most other animations, the facial expression will show a Sims mood. The closer you zoom, the better you will see it. There will also be different sounds for different emotions.

Technical background info

We also got a bit of background info on how animations in Sims 4 were done.

As soon as the animators know what animations are needed, they will play through them and record them (motion capture). The best will then be imported into MAYA where single poses are chosen and changed. The characters in MAYA have 60-80 contact points that are all being manipulated by the animators until it fits their needs. Each animation has a start and an end, kind of a resting position where all animations start and end. The sequences between the poses are calculated by the computer.

The animations are then exported into a format the game can read and then imported. While Sims 3 used a technology called JAZZ for this, Sims 4 has a completely new system called SWING. In SWING it can then be defined, which animation can play in how many loops and in what order they can be played in. They also define which animations are compatible with each other.

As an example we are shown the telling of a scary story. The whole story consists of several parts which are put together in random order by the game. This way it’s possible to tell the same story in different variations.

The creating of small animations sequences allows reusing them at different places in the game. All animations in Sims 4 are new though. There was no recycling done from Sims 2 and Sims 3

Another interesting technical aspect that was explained to us was, how Sims can now sit on most objects in the game. To achieve this, they don’t need to have a new animation each time, but they attach little magnet to the Sims feet that then can be attached to a point on the seating object. Sims can than sit on every object that has those little magnets and the same animations can be used for bed, barstools, chairs, sofas and more.

Why no height sliders?

Different heights are a similar problem to walking from one place to another and turning, only in a different dimension. To make walking as smooth as it is now, they use about 60 animations. Height not only influences the problem of walking but every animation in the game (around 10’000). Each needs to be created and tested. The cost would just be to great (“We would need to hire all of China”)

This means that they need to find a different approach to solve this problem. Unfortunately for Sims 4, they haven’t found one. This is something the devs would love to make, not only because it would be an interesting aspect for the game but also an challenging topic to find a solution to, that can be done with the resources they have. For Sims 4, Maxis has decided to concentrate to give us smooth walking animations and better routing


90% of what was shown in the animations master class did impress and delight me. The smooth animations, the unbelievable routing and the aspects of multitasking and social interactions did personally convince me. We didn’t see it directly in the game, but the shown videos were recorded in game and Marion did say over and over that everything she showed us does really work in the game.

There are two things which I didn’t like as much. One was the social interaction where two Sims sit on a bed and talk to each other. Both had their feet on the ground but turned their body to face each other. This looked very unnatural to me.

The other thing was the disappearance of things when Sims talk with too many gestures or when they need both hands to eat. We all know that this can be an issue as well in real life and you sometimes have to look for a place to put stuff. This may be too costly for the game but the disappearing objects remind me too much of Sims pulling everything (including cars) out of their butt and makes me fear that this aspect of Sims 3 will still be very present in Sims 4. I’m aware that it might be difficult to find a solution that is efficient and also looks good (I have to admit that I can’t remember how that was in Sims 2)

Two thumbs up for the animations. I truly hope that stuck Sims and routing failures ARE a thing of the past.

Further Reading