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How to enable Chaos

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    If anybody would like to use Chaos, I guess it's best to switch the branch to 4.26-chaos. It's regularly updated with Chaos fixes/improvements.


      Originally posted by Moth Doctor View Post
      If anybody would like to use Chaos, I guess it's best to switch the branch to 4.26-chaos. It's regularly updated with Chaos fixes/improvements.
      I compiled the source and it is working great.


        The Unreal Engine 4.26-Chaos Preview is now available on the Epic Games launcher - test out Chaos without compiling from source!

        If you’ve been itching to give the Chaos Physics and Destruction System a try, without needing to compile source, now you can—head to the Epic Games launcher and install Unreal Engine 4.26-Chaos Preview from the list of available versions in the install dropdown. In this binary build, Chaos replaces PhysX for all physics simulations, including cloth, vehicles, and destruction.

        Note: 4.26-Chaos can be found at the bottom of the dropdown.

        If you give a shot, please help us make the system the best it can be by filing bugs and sharing your feedback. Thanks all!


          On 4.26, I enable the Chaos plugin in UE4Editor.Target.cs by setting bCompileChaos = true and bUseChaos = true but.......

          1. IF I set this line BuildEnvironment = TargetBuildEnvironment.Unique like this with Unique instead of Shared it crashes the editor on boot on line checkf(!bInitializedSerializationHistory, TEXT("Shader Type was loaded after engine init...")), and I cannot seem to make it work. DOES NOT EVEN BOOT THE EDITOR!
          2. IF I set this line BuildEnvironment = TargetBuildEnvironment.Unique to .Shared instead of Unique, the editor then boots, I have Chaos enabled I can see the FRACTURE mode I can do stuff with it, buuuuuut apparently does not work with C++ projects, as everytime I try to compile, the compiler fails, giving me the error that I should use the .Unique build environment or another boolean that forces the environment to unique, soooo either way, for me this plugin doesn't seem to work how I want it....I just want a C++ project (because I created it like this a long time ago) and I can't seem to make it work for C++.....HALP!


            VictorLerp could anyone from the epic crew post at least a screenshot please of how to use "ActivateDisabled" field in order to activate once disabled objects/fragments with DisableTreshold field ? We are making a pretty big game with chaos (it's pretty much chaos demo) and we need this field, and there is literally nothing anywhere on this field. I am not sure if it's bugged or I just can't make it to work on 4.26. Thanks!
            PS The way on the image doesn't work.
            Attached Files
            Last edited by Bartek77; 12-29-2020, 06:25 PM.


              Hello, everyone!
              Finally got to Chaos. Thanks to a release in the Launcher.
              Started looking into it, and encountered this strange behavior, not at all like in the lecture, when falling collection immediately "explodes" instead of collapsing under its own weight.
              Tried experimenting with different weights, did not see any difference.
              Any ideas how to fix it?
              And how to work with the mass on the example of a standard column from the demo?

              Translated with (free version)


                As development of Chaos Destruction moves forward, some defaults may get changed around. In this case, the pillar looks to have been defaulted to Box Collision, and boxes are wrapped around every cluster and child node. Since Box collision envelops each body, they typically have large amounts of overlap, and so their first action on a fully dynamic object such as this is to push apart from one another.

                You can do a few things to mitigate this behaviour in the asset itself. One of these is to use Collision Object Reduction Percentage, which will shrink those boxes and make this effect far less pronounced. Try 40 or so to see this effect...

                The most accurate method, however, is to switch the Collision Type to LevelSet, this will create an accurate virtual representation of each body and cluster, and this behaviour will improve greatly, since the collision bodies will no longer overlap. The Chaos Destruction Content examples has a map about Geometry Collections and should give a pretty good grounding in what these collision types are doing.