How to enable Chaos

[Rainoxer]

General perf question for everyone. There seems to be a perf gap since the 4.23 release of chaos, at least within the test levels. On the order of 10-12ms increase for the same content. And in some instances what had been running smoothly in 4.23 (the scripted destruction of the building in the "Geometry_Collections" level) can dip way down into the red, teens and single digits in 4.24 and 4.25.

I'm assuming this is true for everyone else and not something specific to my build(s). Is that correct?

I didn't manage to get the demo running in 4.23 but I tried it in 4.25 and yeah, the performances are terribly bad. In 4.23 I remember the destruction was lagging a lot but not the framerate because the destruction was happening in a separated thread, however in 4.25 it seems the destruction impacts the frame rate... I reached 5-10 FPS when running through a showroom to activate all triggers in the same time.

[catalejo]

Hello. I was able to compile 4.25 with the template demo following the instructions but when i run the default map, it starts fine but it crashes once it starts simulating (after pressing a button in the map), any pointers?

[X Grigry X]

I have compiled the source for 4.25. And created the project for Chaos for 4.25. I need an explicit explanation on getting Chaos to work with 4.25. Thanks.

Did you get your explanation? Because I can't make it work here... Could you show the different steps please?

[RoboticHuman]

Did you get your explanation? Because I can't make it work here... Could you show the different steps please?

Seems like the only possible way through my experiments is to use the variable bOverrideBuildEnvironment in your project EditorTarget cs file.

bCompileChaos = true;
bUseChaos = true;
bOverrideBuildEnvironment = true;

I don't understand this setting so much really as it basically skips the validation of modules that require a unique build when using a shared build of the engine but it does compile and start the engine at least. I really hope we hear something from some devs here

[Rainoxer]

Seems like the only possible way through my experiments is to use the variable bOverrideBuildEnvironment in your project EditorTarget cs file.

bCompileChaos = true;
bUseChaos = true;
bOverrideBuildEnvironment = true;

I don't understand this setting so much really as it basically skips the validation of modules that require a unique build when using a shared build of the engine but it does compile and start the engine at least. I really hope we hear something from some devs here

My 4.25 demo runs if I follow the documentation's steps. However, if I want to launch it from the UE4Editor.exe I generated, it tells me "this project was built with a different engine, rebuilt now?" and then the rebuild fails.

My ChaosDestructionDemoEditor.Target.cs file contains this :

Type = TargetType.Editor;

ExtraModuleNames.AddRange( new string[] { "ChaosDestructionDemo" } );

bCompileChaos = true;
bUseChaos = true;
bCompilePhysX = true;
bCompileAPEX = true;
bCompileNvCloth = true;
bCustomSceneQueryStructure = true;
BuildEnvironment = TargetBuildEnvironment.Unique;

Unreal told me there was a problem with

bUseChaos = true;

and told me to use

BuildEnvironment = TargetBuildEnvironment.Unique;

or

bOverrideBuildEnvironment = true;

but both did not work, I had to remove

bUseChaos = true;

. Now the engine tells me "ChaosDestructionDemo could not be compiled. Try rebuilding from source manually."...







To resume, I can work with the demo by following the documentation's steps, but it requires to keep a dedicated engine only for it because there is a problem with this step from the documentation :
"6. Build the ChaosDestructionDemo for Development Editor (should be the default Visual Studio configuration). This will build the whole engine, with Chaos, since it's already setup in the project's Target file." -> this does not generate an UE4Editor.exe

So I have a 2nd engine I built the "classic" way, with Chaos working great and a generated .exe, but I cannot open the Demo with this one... Really weird.

[RoboticHuman]

VictorLerp, Can you please help with enabling Chaos in 4.25? It seems a lot of people are facing issues but no one is responding from Epic's side

[Rainoxer]

VictorLerp, Can you please help with enabling Chaos in 4.25? It seems a lot of people are facing issues but no one is responding from Epic's side

Just follow the documentation steps, enabling Chaos is very easy.
The problem is the demo.

[GollumZz]

I still has problems to run ChaosDestructionDemo, does that have a way to work?
my steps are
1, download the unreal engine from github, branch 4.25.0-release
2, follow the guide, modify UE4Editor.Target.cs and build UE4 with Chaos, https://docs.unrealengine.com/en-US/...iew/index.html
3, download ChaosDestructionDemo project and generate sln file with 4.25 engine
4, build and run, the problem happened with below

LogInit: Display: Running incorrect executable for target. Launching Unreal Projects/ChaosDestructionDemo/Binaries/Win64/ChaosDestructionDemoEditor.exe...
LogCore: Engine exit requested (reason: EngineExit() was called)
LogExit: Preparing to exit.

My UE4Editor.Target.cs looks like below

public UE4EditorTarget( TargetInfo Target ) : base(Target)
{
Type = TargetType.Editor;
BuildEnvironment = TargetBuildEnvironment.Unique;
bBuildAllModules = true;
ExtraModuleNames.Add("UE4Game");
bCompileChaos = true;
bUseChaos = true;
bOverrideBuildEnvironment = true;
}

I also tried to change BuildEnvironment = TargetBuildEnvironment.Shard, but this will make ChaosDestructionDemo as a zombie process.

[flioink]

GitHub link appears to be dead, at least on my end.

[WorillaGorilla]

GitHub link appears to be dead, at least on my end.

Your GitHub is not linked with your Unreal Engine account
try this:

https://www.unrealengine.com/en-US/ue4-on-github
https://docs.unrealengine.com/en-US/...ine/index.html

[DarknessFX]

I just got Chaos working on UE4.25.
The UnrealEngine-4.25.0-release.zip from github did not work for me (shader errors, LogMrMesh declared twice errors, etcs), I use git clone to get the most recent version.
This is my UE4Editor.Target.cs that build successfully:
==
// Copyright Epic Games, Inc. All Rights Reserved.
using UnrealBuildTool;
using System.Collections.Generic;
public class UE4EditorTarget : TargetRules
{
public UE4EditorTarget( TargetInfo Target ) : base(Target)
{
Type = TargetType.Editor;
//BuildEnvironment = TargetBuildEnvironment.Unique;
BuildEnvironment = TargetBuildEnvironment.Shared;
bBuildAllModules = true;
ExtraModuleNames.Add("UE4Game");
bCompileChaos = true;
bUseChaos = true;
bOverrideBuildEnvironment = true;
}
}
==
To run the Demo:
With the UE425+Chaos editor working, build a Blank Project and then copy the ChaosDestructionDemo423\Content folder to this new project Blank\Content folder, this is the easier way (that I found) to run the Demo without problems.
--
Update: It's working on 4.25.1 too.

[theProfessor]

Using 4.25.1 from the launcher. Noticed under physics their is GC. Did it and it works. No fracture in modes????? In the compiled version the fracture is there.

[LumberingTroll]

Using 4.25.1 from the launcher. Noticed under physics their is GC. Did it and it works. No fracture in modes????? In the compiled version the fracture is there.

I don't think Chaos is active in the binary yet, you need the source from Git.

[ThirdEyeAgent]

Just tried all the steps above for ue4 4.24.3 and 4.25.1 both times the chaos demo fails, it won’t let me enter the last part with the building says something about a cache, tried removing the barrier but nothing happens to the second building. Can someone just post a video. My specs are a gtx 1060 6gb i7 16gb ram.

[BaronS_88]

I successfully built 4.25.1 and the plugin is "working". The problem is that even a small box fractured in 20 pieces literally destroy fps to near 5-10 until the box is completely broken, plus, even other objects are completely bugged and start moving on the floor with no reason at all as if they were pieces of ice on a floor completely covered in oil. This was supposed to be a significant improvement from previous version and it ended up being a tremendous joke considerning that all this crazy things wasn't happening with 4.24. And they call it "High performance physics". My willing to learn this engine is decreasing with each release.