Batman Arkham Series "Active Ragdoll" Animation System

Is there any information about what kind of animation system the Batman Arkham series uses? It looks as if Inverse Kinematics was used for aligning Batman’s limbs to the “contact points” on enemies but it is unclear what animation method was used to get the realistic hit reactions.

Unreal Engine 3 & 4 both support Morpheme with Euphoria however Rocksteady was able to pull off what seems like “active ragdolls” using an alternative method to Natural Motion’s “Dynamic Motion Synthesis”. Such As; “parametric motions”, “Dynamic Response for Motion Capture Animation”, “SIMBICON: Simple Biped Locomotion Control”?


I might be way off here, but I would try using some generic staggering animation, then having specific bones simulate physics (entire upper body or head and arm, etc), apply an impulse from Batman’s fist (or whatever), then set the physics blend weight gradually back to 0 (after they’ve recovered completely). And I suppose you could use IK to move whatever arm wasn’t hit towards the location of the hit with some relatively simple calculations.

So you are suggesting to have the specific bones around the area that got “impacted” to simulate a physical reaction by using Inverse Kinematics? Does Epic plan on releasing any detailed documentation about this sort of application of IK? Or maybe even some tutorials? It seems logical for Epic to atleast acknowledge this limitation of their engine’s physics based animations let alone suggest some alternative solution to the problem.

I really love the way Batman : AA does their combat, and I’ve been looking into mixing ragdoll and animation.
Here are some things I’ve found :
You can easily animate the blend value with a timeline, like @Bohrium said. You could even set the torso to ragdoll, then turn off the arms’ ragdoll and play a flailing or head grabbing animation when downed. Which in theory could achieve a batman-esque effect. IK would also work, and if you wanted to get fancy you could layer that into the downed animation.

For that gorgeous Natural Motion stagger, you’re probably want to do some stagger animations for directional hits, and blend in the hit bones’ ragdolls.

Epic has a good article on this subject here:

One thing to note is that playing an animation and blending a ragdoll on the hip/root bones can cause weird things to happen, or I might’ve setup my ragdoll incorrectly.


This is a short clip that shows a relatively static backwards staggering animation with an over exaggerated force applied over several frames (the twitching is due to that and it’s nowhere near as strong in the editor as the clip for some reason). The upper body (from spine1 upwards) is set to physics blend on hit with weight 1 decreasing over 3 seconds back to weight 0. The reason it’s clipping through the floor a bit is due to a hastily cobbled together animation and not the physics blending.

I thought that IK could be used as a way of directing a hand towards the hit location, but it would be easier to just have animations and tweak those with IK, than to use IK itself to dynamically animate an entire limb through scripting.

That seems quite close, and I bet with the right amount of tweaking, you could get some really nice results.

Check the content examples that comes with the engine…there’s a ragdoll slider for one of the animations if I recall correctly…just a limb so I’m sure if you find that actor in the content browser (right click …find in content browser) I’d imagine you could learn plenty about how Epic goes about doing something like the Arkham games…

Thank You for all the helpful replies I am still looking into this, though I just thought I would mention that although affecting a group of bones around the impact area works in some cases I was hoping there was some kind of built in Full Body IK feature as an alternative to HumanIK gameware plugin. Here is a video (starting at 2:00 min to show kind of what I mean) basically the whole body is reacting to the impact not just group of bones in area.


I dont think there is any full body IK integrated into the engine. There is however something called IKinema, but its a plugin with a strange subscription pricing plan and I dont recommend it.

I have also been trying to get an active ragdoll working. Id like to be able to simulate a ragdoll, but also have animation data playing on some of the bones. So for a death animation I could animate a character curling up and squirming, and have that animation data be playing on a ragdoll, and then slowly decrease the blend weights, or something like that.