Announcement

**NurtNurt** · 10-08-2015, 07:33 PM

Cannot thank you enough, getnamo! i was probably waay too excited when i saw you had updated, things seem to run beautifully now, even in conjunction with the rift, seriously generous and awesome.
if there is some other way i and the others who benefit from your work let me know (patreon, donations etc..) you're enabling us to develop for the next wave of VR interaction at a time when the upcoming hardware is simply unavailable to us.
You rock.
so much.

**LNaej** · 10-18-2015, 11:07 AM

Just tested your last update, it works like a charm on 4.9.2, especially the calibration. Saves a lot of time, a big thanks to you getnamo.

**san** · 11-04-2015, 09:42 AM

getnamo, thanks for your work on this plugin!

However I've encounter quite a nasty issue with the plug-in (4.9 experimental branch on UE4 4.9.2). It might be a generic UE4 plug-in issue and not related to your work but perhaps (hopefully) you are familiar with the issue.

When I integrate the plug-in in an existing project we're getting errors every time we open the project. Actors that make use of the HydraComponent (so not the generic MotionController events) are broken. For some unknown reason the component is not found and thus all functionality related to it is removed from the Actors Blueprint.

When inspecting the logs I noticed this:

Code:

LogLinker:Warning: Can't find file '/Script/HydraPlugin'
LogLinker:Warning: Can't find file for asset '/Script/HydraPlugin' while loading D:/Unreal/AwesomeGameProject/Content/Assets/Graphics/Models/Characters/Godzilla01_Skeleton_AnimBlueprint.uasset.
LoadErrors:Error: Error /Game/Assets/Graphics/Models/Characters/Godzilla01_Skeleton_AnimBlueprint : Can't find file for asset. /Script/HydraPlugin
LogLinker:Warning: Can't find file '/Script/HydraPlugin'
LogLinker:Warning: Can't find file for asset '/Script/HydraPlugin' while loading D:/Unreal/AwesomeGameProject/Content/Assets/Graphics/Models/Characters/Godzilla01_Skeleton_AnimBlueprint.uasset.
LoadErrors:Error: Error /Game/Assets/Graphics/Models/Characters/Godzilla01_Skeleton_AnimBlueprint : Can't find file for asset. /Script/HydraPlugin
LogLinker:Warning: Can't find file '/Script/HydraPlugin'
...
HydraPluginLog: Attempting to startup Hydra Module, v0.8.2
HydraPluginLog: Fetching dll from E:/Documents/Unreal Projects/HydraTest/Plugins/HydraPlugin/Source/ThirdParty/Sixense/Binaries/Win64/sixense_x64.dll
HydraPluginLog: Hydra Available.

It appears that the plug-in is loaded after the assets are loaded. Might this be the issue? If it is, do you know of a fix / work-around?
When we tried your plug-in using a blank C++ project all seems to work fine... however starting over is not really an option. Especially when there is no guarantee that it will not reappear.
The project started off as a Blueprint project and we've added C++ code later on. This should not matter but you never know.

Sorry for this "cry for help" kind of post but WHELP!

**redhead** · 11-18-2015, 09:48 AM

hi getnamo do you plan to release a compiled version for 4.10 soon ?
Your stuff is amazing so far but we have trouble with 4.9 and like to use the new features of 4.10!

**getnamo** · 11-20-2015, 03:06 PM

Update to 0.8.3
-Updated to 4.10
-Experimental branch merged into master

The experimental branch changes are now in master so if you haven't tried them, the 0.8+ plugin version works quite differently and I recommend you read the github readme and this thread to bring you up to speed.

@Everyone Thanks for all the kind words of appreciation, now go make awesome stuff with 4.10!

Originally posted by san View Post

getnamo, thanks for your work on this plugin!

However I've encounter quite a nasty issue with the plug-in (4.9 experimental branch on UE4 4.9.2). It might be a generic UE4 plug-in issue and not related to your work but perhaps (hopefully) you are familiar with the issue.

When I integrate the plug-in in an existing project we're getting errors every time we open the project. Actors that make use of the HydraComponent (so not the generic MotionController events) are broken. For some unknown reason the component is not found and thus all functionality related to it is removed from the Actors Blueprint.

When inspecting the logs I noticed this:

Code:

...

It appears that the plug-in is loaded after the assets are loaded. Might this be the issue? If it is, do you know of a fix / work-around?
When we tried your plug-in using a blank C++ project all seems to work fine... however starting over is not really an option. Especially when there is no guarantee that it will not reappear.
The project started off as a Blueprint project and we've added C++ code later on. This should not matter but you never know.

Sorry for this "cry for help" kind of post but WHELP!

Haven't seen this before, you may need to break down the loading or shrink the problem size by trying to recreate the problem from a blank state. Once you have a reliable repro I can take a look into it.

**redhead** · 11-21-2015, 08:04 AM

YES

Thanks a lot !

**LaP0573** · 11-24-2015, 02:29 PM

Hello,
I've used the plugin for a gamejam, as well as VR stuff, and I'd like to package my project now to create a .exe. I get these errors while packaging, and from what I understand they seem to be linked to the Hydra plugin :

Code:

MainFrameActions: Packaging (Windows (64-bit)): Project.Build: ********** BUILD COMMAND STARTED **********
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.Build: XGE was requested, but is unavailable, so we won't use it.
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.Build: ************************* UE4Build:
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.Build: ************************* ForceMonolithic: False
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.Build: ************************* ForceNonUnity:False 
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.Build: ************************* ForceDebugInfo: False
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.Build: ************************* UseXGE: False
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.Build: ************************* UseParallelExecutor: False
MainFrameActions: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files\Epic Games\4.10\Engine\Binaries\DotNET\UnrealBuildTool.exe TestMotionSickness Win64 Development -clean "F:\Data\Projects\UE4\TestMotionSickness - Copie\TestMotionSickness.uproject"  -remoteini="F:\Data\Projects\UE4\TestMotionSickness - Copie" -nobuilduht -rocket -NoHotReloadFromIDE
MainFrameActions: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 2,7106767s to run UnrealBuildTool.exe, ExitCode=0
MainFrameActions: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files\Epic Games\4.10\Engine\Binaries\DotNET\UnrealBuildTool.exe TestMotionSickness Win64 Development  "F:\Data\Projects\UE4\TestMotionSickness - Copie\TestMotionSickness.uproject"  -remoteini="F:\Data\Projects\UE4\TestMotionSickness - Copie" -noxge -generatemanifest -rocket -NoHotReloadFromIDE -ignorejunk
MainFrameActions: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 1,2134635s to run UnrealBuildTool.exe, ExitCode=0
MainFrameActions: Packaging (Windows (64-bit)): UE4Build.PrepareManifest: Copied UBT manifest to C:\Users\Faust\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+4.10\UBTManifest.0.xml
MainFrameActions: Packaging (Windows (64-bit)): CommandUtils.Run: Run: C:\Program Files\Epic Games\4.10\Engine\Binaries\DotNET\UnrealBuildTool.exe TestMotionSickness Win64 Development  "F:\Data\Projects\UE4\TestMotionSickness - Copie\TestMotionSickness.uproject"  -remoteini="F:\Data\Projects\UE4\TestMotionSickness - Copie" -noxge -rocket -NoHotReloadFromIDE -ignorejunk
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: Creating makefile for TestMotionSickness (no existing makefile)
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: Performing full C++ include scan (no include cache file)
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: Parsing headers for TestMotionSickness
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool:   Running UnrealHeaderTool "F:\Data\Projects\UE4\TestMotionSickness - Copie\TestMotionSickness.uproject" "F:\Data\Projects\UE4\TestMotionSickness - Copie\Intermediate\Build\Win64\TestMotionSickness\Development\UnrealHeaderTool.manifest" -LogCmds="loginit warning, logexit warning, logdatabase error" -rocket -installed
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: Reflection code generated for TestMotionSickness in 5,6982198 seconds
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: Performing 10 actions (4 in parallel)
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: PCH.HydraPluginPrivatePCH.h.cpp
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: PCH.UELinkerFixupsName.h.cpp
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\crtdefs.h(10): fatal error C1083: Cannot open include file: 'corecrt.h': No such file or directory
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: UELinkerFixups.cpp
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: -------- End Detailed Actions Stats -----------------------------------------------------------
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: ERROR: UBT ERROR: Failed to produce item: F:\Data\Projects\UE4\TestMotionSickness - Copie\Plugins\HydraPlugin\Binaries\Win64\UE4-HydraPlugin.lib
MainFrameActions: Packaging (Windows (64-bit)): UnrealBuildTool: Total build time: 17,02 seconds
MainFrameActions: Packaging (Windows (64-bit)): CommandUtils.Run: Run: Took 17,0528513s to run UnrealBuildTool.exe, ExitCode=5
MainFrameActions: Packaging (Windows (64-bit)): BuildCommand.Execute: ERROR: BUILD FAILED
MainFrameActions: Packaging (Windows (64-bit)): Program.Main: ERROR: AutomationTool terminated with exception:
MainFrameActions: Packaging (Windows (64-bit)): Program.Main: ERROR: Exception in AutomationUtils.Automation: Command failed (Result:5): C:\Program Files\Epic Games\4.10\Engine\Binaries\DotNET\UnrealBuildTool.exe TestMotionSickness Win64 Development  "F:\Data\Projects\UE4\TestMotionSickness - Copie\TestMotionSickness.uproject"  -remoteini="F:\Data\Projects\UE4\TestMotionSickness - Copie" -noxge -rocket -NoHotReloadFromIDE -ignorejunk. See logfile for details: 'UnrealBuildTool-2015.11.24-19.23.39.txt' 
MainFrameActions: Packaging (Windows (64-bit)): Stacktrace:    à AutomationTool.CommandUtils.RunAndLog(String App, String CommandLine, String Logfile, Int32 MaxSuccessCode, String Input, ERunOptions Options, Dictionary`2 EnvVars)
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.CommandUtils.RunUBT(CommandEnvironment Env, String UBTExecutable, String CommandLine, String LogName, Dictionary`2 EnvVars)
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.UE4Build.BuildWithUBT(String ProjectName, String TargetName, UnrealTargetPlatform TargetPlatform, String Config, String UprojectPath, Boolean ForceMonolithic, Boolean ForceNonUnity, Boolean ForceDebugInfo, Boolean ForceFlushMac, Boolean DisableXGE, String InAddArgs, Boolean ForceUnity, Dictionary`2 EnvVars)
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.UE4Build.Build(BuildAgenda Agenda, Nullable`1 InDeleteBuildProducts, Boolean InUpdateVersionFiles, Boolean InForceNoXGE, Boolean InUseParallelExecutor, Boolean InForceNonUnity, Boolean InForceUnity, Boolean InShowProgress, Dictionary`2 PlatformEnvVars)
MainFrameActions: Packaging (Windows (64-bit)):    à Project.Build(BuildCommand Command, ProjectParams Params, Int32 WorkingCL)
MainFrameActions: Packaging (Windows (64-bit)):    à BuildCookRun.DoBuildCookRun(ProjectParams Params)
MainFrameActions: Packaging (Windows (64-bit)):    à BuildCommand.Execute()
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.Automation.Execute(List`1 CommandsToExecute, CaselessDictionary`1 Commands)
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.Automation.Process(String[] CommandLine)
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.Program.MainProc(Object Param)
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.InternalUtils.RunSingleInstance(Action`1 Main, Object Param)
MainFrameActions: Packaging (Windows (64-bit)):    à AutomationTool.Program.Main()
MainFrameActions: Packaging (Windows (64-bit)): ProcessManager.KillAll: Trying to kill 0 spawned processes.
MainFrameActions: Packaging (Windows (64-bit)): Program.Main: AutomationTool exiting with ExitCode=5
MainFrameActions: Packaging (Windows (64-bit)): Domain_ProcessExit
MainFrameActions: Packaging (Windows (64-bit)): copying UAT log files...
MainFrameActions: Packaging (Windows (64-bit)): RunUAT.bat ERROR: AutomationTool was unable to run successfully.
MainFrameActions: Packaging (Windows (64-bit)): BUILD FAILED

Any idea ?

**astonish** · 11-24-2015, 02:55 PM

Originally posted by san View Post

getnamo, thanks for your work on this plugin!
When I integrate the plug-in in an existing project we're getting errors every time we open the project. Actors that make use of the HydraComponent (so not the generic MotionController events) are broken. For some unknown reason the component is not found and thus all functionality related to it is removed from the Actors Blueprint.

I'm now seeing this same problem on 4.9. Everything was working fine in my BP only prototype, but as soon as I changed to a C++ project (and then made a BP pawn set as default via C++ GameMode) this appears every open. My project is early enough along that I will try your 4.10 branch

**astonish** · 11-24-2015, 04:21 PM

getnamo,

I have been able to replicate the problem consistently from a fresh project. Here are the steps using 4.9 and the experimental branch from the other thread. I don't have UE 4.10 downloaded yet so I haven't tried it with your new plugin. It seems to be 100% an order of operations problem as the log in this post will show. C++ game mode classes seem to be loaded before the hydra plugin causing the issue when they try loading the BP pawn that refers to the yet-to-be-loaded HydraPlugin.

Code:

1. Make a new blank C++ project
2. Close the editor, add Hydra plugin
3. Reopen editor, Edit->Plugins confirm hydra plugin is loaded
4. Make a blueprint game mode "MyBlueprintgame" (in root "Content" folder)
5. Make a blueprint pawn "MyHydraPawn" (in root "Content" folder)
6. Open MyHydraPawn. Add HydraPlugin component.
    a. To BeginPlay add a is hydra available node and make it print something the screen
7. Save all
8. Open MyBlueprintGame and make the default pawn "MyHydraPawn" (might have to open the bp twice to get the right options to appear)
9. Edit->Project Settings... -> Maps & Modes make MyBlueprintGame the gameMode
10. P.I.E. and see that your debug print statement shows.
11. Save All then exit the editor
12. Reopen the editor. No error messages, P.I.E. and ensure print statement still shows
13. Make a new C++ class, GameMode, MyCGameMode
14. In Visual studio add a default constructor AMyCGameMode() make a definition with a blank body in the .cpp file.
15. Compile.
16. Go back to the editor. Save all. exit.
17. Reload editor. No errors. Run, see debug message.
18. In visual studio add the following code to the default constructor:
    static ConstructorHelpers::FObjectFinder<UBlueprint> razrbp(TEXT("Blueprint'/Game/MyRazorPawn.MyRazorPawn'"));
    if (razrbp.Object) {
               DefaultPawnClass = (UClass*)razrbp.Object->GeneratedClass;
    }
19. Compile. P.I.E. everything is still fine.
20. Save all, close editor.
21. Open editor. Error messages appear saying "/Game/MyRazorPawn: Can't find file for asset. /Script/HydraPlugin"
22. P.I.E. also presents errors with BP compile
23. Opening MyRazorPawn class show the class is now missing a HydraPlugin component.

Note that this is happening even though the default gameMode is still the blueprint version and not the C++ version. Add the HydraPluging back to the BP pawn and everything will run fine until you close the editor and reopen.

Trying to set default pawn class at StartMatch() in the C++ GameMode crashes everything. I suppose I could try spawning a instance of the BP pawn and then attaching the player controller at StartMatch, but this error may still persist loading the editor... Here is the log from the editor launching with errors. You can clearly see the missing script errors output before the Hydra plugin begins init.

Pastebin

This may expected behaviour of the engine, I don't really know much about startup order, but for my project I'd really like to have a C++ game mode refer to a BP pawn that uses your (great) plugin.

**LaP0573** · 11-24-2015, 08:25 PM

I've opened an issue on your GitHub, but not sure it was a good idea after reading that you advised polling problems into this thread, so I'll reiterate my question here. I've packaged a game with your plugin, copy pasted the plugin folder into the packaged game but I get this crash when starting the .exe :

Code:

MachineId:595E01B1444ED99F3D293181649D4B6D
EpicAccountId:

Access violation - code c0000005 (first/second chance not available)

""

TestMotionSickness_Win64_Shipping!FHydraPlugin::DataDelegate() [f:\data\projects\ue4\testmotionsickness - copie\plugins\hydraplugin\source\hydraplugin\private\fhydraplugin.cpp:855]
TestMotionSickness_Win64_Shipping!UHydraPluginComponent::InitializeComponent() [f:\data\projects\ue4\testmotionsickness - copie\plugins\hydraplugin\source\hydraplugin\private\hydracomponent.cpp:21]
TestMotionSickness_Win64_Shipping!AActor::InitializeComponents()
TestMotionSickness_Win64_Shipping!AActor::PostActorConstruction()
TestMotionSickness_Win64_Shipping!AActor::FinishSpawning()
TestMotionSickness_Win64_Shipping!AActor::PostSpawnInitialize()
TestMotionSickness_Win64_Shipping!UWorld::SpawnActor()
TestMotionSickness_Win64_Shipping!UWorld::SpawnActor()
TestMotionSickness_Win64_Shipping!AGameMode::SpawnDefaultPawnFor_Implementation()
TestMotionSickness_Win64_Shipping!AGameMode::execSpawnDefaultPawnFor()
TestMotionSickness_Win64_Shipping!UFunction::Invoke()
TestMotionSickness_Win64_Shipping!UObject::ProcessEvent()
TestMotionSickness_Win64_Shipping!AActor::ProcessEvent()
TestMotionSickness_Win64_Shipping!AGameMode::SpawnDefaultPawnFor()
TestMotionSickness_Win64_Shipping!AGameMode::RestartPlayer()
TestMotionSickness_Win64_Shipping!AGameMode::HandleMatchHasStarted()
TestMotionSickness_Win64_Shipping!AGameMode::SetMatchState()
TestMotionSickness_Win64_Shipping!UWorld::BeginPlay()
TestMotionSickness_Win64_Shipping!UEngine::LoadMap()
TestMotionSickness_Win64_Shipping!UEngine::Browse()
TestMotionSickness_Win64_Shipping!UGameInstance::StartGameInstance()
TestMotionSickness_Win64_Shipping!UGameEngine::Init()
TestMotionSickness_Win64_Shipping!FEngineLoop::Init()
TestMotionSickness_Win64_Shipping!GuardedMain()
TestMotionSickness_Win64_Shipping!GuardedMainWrapper()
TestMotionSickness_Win64_Shipping!WinMain()
TestMotionSickness_Win64_Shipping!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

Any idea ?

**getnamo** · 11-25-2015, 06:34 AM

Look's like bug fixing is back on the menu boys!

Originally posted by LaP0573 View Post

I've opened an issue on your GitHub, but not sure it was a good idea after reading that you advised polling problems into this thread, so I'll reiterate my question here. I've packaged a game with your plugin, copy pasted the plugin folder into the packaged game but I get this crash when starting the .exe :

Code:

...

Any idea ?

The packaging bug seems like an order problem, the DataDelegate() call at 855 gets called before the reference is set. It will need some moving around and checking load orders in packaged games.

Originally posted by astonish View Post

getnamo,

I have been able to replicate the problem consistently from a fresh project. Here are the steps using 4.9 and the experimental branch from the other thread. I don't have UE 4.10 downloaded yet so I haven't tried it with your new plugin. It seems to be 100% an order of operations problem as the log in this post will show. C++ game mode classes seem to be loaded before the hydra plugin causing the issue when they try loading the BP pawn that refers to the yet-to-be-loaded HydraPlugin.

Code:

...

Note that this is happening even though the default gameMode is still the blueprint version and not the C++ version. Add the HydraPluging back to the BP pawn and everything will run fine until you close the editor and reopen.

Trying to set default pawn class at StartMatch() in the C++ GameMode crashes everything. I suppose I could try spawning a instance of the BP pawn and then attaching the player controller at StartMatch, but this error may still persist loading the editor... Here is the log from the editor launching with errors. You can clearly see the missing script errors output before the Hydra plugin begins init.

Pastebin

This may expected behaviour of the engine, I don't really know much about startup order, but for my project I'd really like to have a C++ game mode refer to a BP pawn that uses your (great) plugin.

Great investigation, this will help narrow potential issue scope. Let me know if 4.10 has the same issue.

Will have a look at these during the weekend, I want this new structure to be as solid as the last one.

**astonish** · 11-25-2015, 03:29 PM

Originally posted by getnamo View Post

Let me know if 4.10 has the same issue.

Just tried 4.10 with the new plugin and I have the same issue if I follow the steps from my previous post. I'm hopeful I can easily work around it by either creating a type of that pawn at runtime, or grabbing a reference to a pre-placed one in the level and then possessing it with the player controller, but I don't have the time today to test. It would still be nice to just use the "DefaultPawnClass" assignment. Less work/code

**JPStark** · 11-30-2015, 12:52 AM

I'm working on a block stacking puzzle game that's similar to Boom Blox, but I've been stuck for a while on a weird rotation bug. I figured this would be the place to ask for help, so, here's a quick rundown of my setup:

The camera pivots around a stack of blocks on a spring arm system that's based off the 3rd person templet. You can zoom the FoV in/out and as the camera pan up/down the stack. The "grabbing hand" is motion controlled by the hydra, but its central base coordinate is relative to a point on a spring arm in front of the camera. As the camera pivots around the tower, the Hydra's base coordinate stays in front of your perspective. I've been able to get this system working nicely, and I made a demo to show it:

https://youtu.be/pvMyJCk5rsI?t=64

Unfortunately, there is a weird bug that I was trying to hide it in that video. Let's say I grab a block with my hydra and I want to tilt the far side upwards... If I tilt my hydra up, you would expect to see the far side of the block tilt up in a corresponding fashion, but it that doesn't always happen that way. Sometimes the wrong part of the block begins to tilt up and my brain overheats as I try to figure out how my real world hand rotation affects the in-game block rotation. Here's a video of the problem in action:

https://www.youtube.com/watch?v=6DImCdw3Bno

As you can see, it doesn't actually matter what angle I'm looking at the block from. When I grab a block, its orientation in relation to the hydra will be determined by that block's rotational yaw at the moment I grab it. I need to get the block's orientation to correspond with my orientation, and I think that means the following:

+ hydra yaw (world)
- actor yaw(world)

Anyhow, I've spent about 10 hours trying to figure out how to do this, but the closest I got was to make the block spin to match my orientation when I grab it and that's no good because it knocks stuff over. I'm trying to get this going as a project for the VR development club I started at my college, but there's no point getting other people working on other stuff when I can't even get the basic motion controller and camera system working. Any help would be greatly appreciated!

Here are my blueprints: http://imgur.com/a/bWAZe

Attached Files

**ionbordura** · 11-30-2015, 07:18 AM

Hi there,

does anyone have a working c++ example / tutorial? I noticed the youtube tutorial or the answer #68 are very outdated.

Thanks,
Andrei

**getnamo** · 11-30-2015, 10:20 AM

Originally posted by JPStark View Post

I'm working on a block stacking puzzle game that's similar to Boom Blox, but I've been stuck for a while on a weird rotation bug. I figured this would be the place to ask for help, so, here's a quick rundown of my setup:

The camera pivots around a stack of blocks on a spring arm system that's based off the 3rd person templet. You can zoom the FoV in/out and as the camera pan up/down the stack. The "grabbing hand" is motion controlled by the hydra, but its central base coordinate is relative to a point on a spring arm in front of the camera. As the camera pivots around the tower, the Hydra's base coordinate stays in front of your perspective. I've been able to get this system working nicely, and I made a demo to show it:

https://youtu.be/pvMyJCk5rsI?t=64

Unfortunately, there is a weird bug that I was trying to hide it in that video. Let's say I grab a block with my hydra and I want to tilt the far side upwards... If I tilt my hydra up, you would expect to see the far side of the block tilt up in a corresponding fashion, but it that doesn't always happen that way. Sometimes the wrong part of the block begins to tilt up and my brain overheats as I try to figure out how my real world hand rotation affects the in-game block rotation. Here's a video of the problem in action:

https://www.youtube.com/watch?v=6DImCdw3Bno

As you can see, it doesn't actually matter what angle I'm looking at the block from. When I grab a block, its orientation in relation to the hydra will be determined by that block's rotational yaw at the moment I grab it. I need to get the block's orientation to correspond with my orientation, and I think that means the following:

+ hydra yaw (world)
- actor yaw(world)

Anyhow, I've spent about 10 hours trying to figure out how to do this, but the closest I got was to make the block spin to match my orientation when I grab it and that's no good because it knocks stuff over. I'm trying to get this going as a project for the VR development club I started at my college, but there's no point getting other people working on other stuff when I can't even get the basic motion controller and camera system working. Any help would be greatly appreciated!

Here are my blueprints: http://imgur.com/a/bWAZe

From your videos it appears as if you're setting the cube rotation in world space but you forget to add the parent actor (pawn) rotation so it will always show as if your hands are 'in front' of the stack. You are using add controller yaw input to pan the camera, which rotates the pawn controller orientation, you need to combine this orientation with the MC orientation to get the expected behavior.

A couple more things
-For best tracking, you shouldn't calibrate hydras rotation, only position. Always have the hydra orientated properly (cables facing away from you perpendicular to your screen, can be off-center, but not off-rotation). This is because if you have a hydra near the base when you calibrate orientation it can be significantly off-center (magnetic field lines bending)
-You shouldn't break rotators and add their floats, instead use the 'combine rotators' or you can end up with a gimbal lock. Combine rotators uses quaternions math, whereas adding doesn't; NB: The order of combine rotators matters, its non-commutative (consider it the difference between the offset affecting the input orientation vs adding a simple offset post input).

Rotations are some of the toughest things to get right, just remember what you're rotating in what space. Btw good job on the clear images and videos, makes it easier to spot problems.

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