VR Expansion Plugin

[Parth Patel]

We are having crash running in the VR Preview. Crash report doesn't mention anything but after looking at the log file, is something related to GripMotionCOntrollerCompoment. Here is Log details:

[2018.03.23-21.15.41:526][ 11]LogWindows: Error: Error reentered: Assertion failed: [File:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp] [Line: 819]
Rendering thread exception:
Assertion failed: !IsUnreachable() [File:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\ScriptCore.cpp] [Line: 1189]
GripMotionControllerComponent /Game/Maps/UEDPIE_0_MASTER.MASTER:PersistentLevel.Vive_PawnCharacter_C_0.Right Grip Motion Controller Function: '/Script/HeadMountedDisplay.MotionControllerComponent:OnMotionControllerUpdated'


0x00000000496A3FB8 KERNELBASE.dll!UnknownFunction []
0x0000000005C57884 UE4Editor-ApplicationCore.dll!UnknownFunction []
0x00000000DE1C6D9B UE4Editor-Core.dll!UnknownFunction []
0x00000000DE101939 UE4Editor-Core.dll!UnknownFunction []
0x00000000DDC08B08 UE4Editor-CoreUObject.dll!UnknownFunction []
0x00000000BA8D34B2 UE4Editor-VRExpansionPlugin.dll!UGripMotionControllerComponent::GripPollControllerState() [d:\parth\unreal\testprojects\vrfour19test\plugins\vrexpansionplugin\vrexpansionplugin\source\vrexpansionplugin\private\gripmotioncontrollercomponent.cpp:3700]
0x00000000BA8F56FC UE4Editor-VRExpansionPlugin.dll!UGripMotionControllerComponent::FGripViewExtension::PreRenderViewFamily_RenderThread() [d:\parth\unreal\testprojects\vrfour19test\plugins\vrexpansionplugin\vrexpansionplugin\source\vrexpansionplugin\private\gripmotioncontrollercomponent.cpp:3749]
0x00000000D4AD6E88 UE4Editor-Renderer.dll!UnknownFunction []
0x00000000D4AAA194 UE4Editor-Renderer.dll!UnknownFunction []
0x00000000DDFDB723 UE4Editor-Core.dll!UnknownFunction []
0x00000000DDFDBD4A UE4Editor-Core.dll!UnknownFunction []
0x00000000085B3CC9 UE4Editor-RenderCore.dll!UnknownFunction []
0x00000000085B4CF6 UE4Editor-RenderCore.dll!UnknownFunction []
0x00000000DE3AA36C UE4Editor-Core.dll!UnknownFunction []
0x00000000DE39F0D3 UE4Editor-Core.dll!UnknownFunction []
0x0000000049911FE4 KERNEL32.DLL!UnknownFunction []
0x0000000049BDEF91 ntdll.dll!UnknownFunction []
0x0000000049BDEF91 ntdll.dll!UnknownFunction []


[2018.03.23-21.15.41:526][ 11]LogWindows: Windows GetLastError: The operation completed successfully. (0)
[2018.03.23-21.15.41:526][ 11]LogThreadingWindows: Error: Runnable thread RenderThread 11 crashed.
[2018.03.23-21.15.41:526][ 11]LogWindows: Error: === Critical error: ===
[2018.03.23-21.15.41:526][ 11]LogWindows: Error:
[2018.03.23-21.15.41:526][ 11]LogWindows: Error: Assertion failed: (GIsCriticalError || !NumMarks) [File:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\Core\Public\Misc/MemStack.h] [Line: 89]
[2018.03.23-21.15.41:526][ 11]LogWindows: Error:
[2018.03.23-21.15.41:526][ 11]LogWindows: Error:
[2018.03.23-21.15.41:526][ 11]LogWindows: Error:
[2018.03.23-21.15.41:526][ 11]LogWindows: Error:
[2018.03.23-21.15.41:526][ 11]LogWindows: Error: Crash in runnable thread RenderThread 11
[2018.03.23-21.15.41:530][ 11]LogWindows: Error: HandleError re-entered.
[2018.03.23-21.15.41:544][ 11]LogExit: Executing StaticShutdownAfterError
[2018.03.23-21.15.41:544][ 11]LogWindows: FPlatformMisc::RequestExit(1)

I grab the 4.19 Plugin from the link on the forum page. Is there new update we are missing?

Thanks,

[mordentral]

We are having crash running in the VR Preview. Crash report doesn't mention anything but after looking at the log file, is something related to GripMotionCOntrollerCompoment. Here is Log details:

[2018.03.23-21.15.41:526][ 11]LogWindows: Error: Error reentered: Assertion failed: [File:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp] [Line: 819]
Rendering thread exception:
Assertion failed: !IsUnreachable() [File:\Build\++UE4+Release-4.19+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\ScriptCore.cpp] [Line: 1189]
GripMotionControllerComponent /Game/Maps/UEDPIE_0_MASTER.MASTER:PersistentLevel.Vive_PawnCharacter_C_0.Right Grip Motion Controller Function: '/Script/HeadMountedDisplay.MotionControllerComponent:OnMotionControllerUpdated'

I grab the 4.19 Plugin from the link on the forum page. Is there new update we are missing?

Thanks,

You grabbed the pre-compiled or the source?

I may have forgot to update the pre-compiled to a version that I fixed an Epic bug in that causes that assert (its not a crash). Its important if you are still getting it on a current source build though because it should be fixed, let me know which one.

I'll package up 4.19 to pre-compiled again though since I think it is missing the fix.

The bug is reported to Epic but I fixed it locally until then.

*Edit* Uploaded a current build to the pre-packed binaries

[sphinix257]

ok so 1 harddrive death later. some backups, and fortunately some recovered files. im back at it. and im still fighting with the arm swinger mode. every time i try to separate it from the mode selector it stops working. so i tried ripping out just what it needs. and i cant figure it out for the life of me. so please take it easy on me. coding is not yet my strengh, its a weakness. how wrong did i do this. and can you help me get this working. ive already got climbing working. i cant get armswinger working.

[mordentral]

ok so 1 harddrive death later. some backups, and fortunately some recovered files. im back at it. and im still fighting with the arm swinger mode. every time i try to separate it from the mode selector it stops working. so i tried ripping out just what it needs. and i cant figure it out for the life of me. so please take it easy on me. coding is not yet my strengh, its a weakness. how wrong did i do this. and can you help me get this working. ive already got climbing working. i cant get armswinger working.

Did you actually hook up the Relative Velocity to get calculated with the lowpass filter?

Also really using both hands it should use both velocities, not just one.

[sphinix257]

Did you actually hook up the Relative Velocity to get calculated with the lowpass filter?

Also really using both hands it should use both velocities, not just one.

edit. i read your statment wrong. im looking at the code again.

im not sure how the velocity works. im pretty sure i got direction.

"Did you actually hook up the Relative Velocity to get calculated with the lowpass filter?"
i couldn't figure that out. i left it the way it was when i found it and couldn't make heads or tails of how it did its job.
im fairly new to coding. getting the forward vector made total sence. but i really don't know what the rest of the code means.

[mordentral]

my bad. only having one hand hooked up was a accident.

"Did you actually hook up the Relative Velocity to get calculated with the lowpass filter?"
i couldn't figure that out. i left it the way it was when i found it and couldn't make heads or tails of how it did its job.
im fairly new to coding. getting the forward vector made total sence and i knew that before i got your code. but i really don't know what the rest of the code means.

There is a function that calculates the relative velocities and runs them through a low pass filter, look for it in the locomotion section, I can't remember the name right now and am away from my pc.

[sphinix257]

There is a function that calculates the relative velocities and runs them through a low pass filter, look for it in the locomotion section, I can't remember the name right now and am away from my pc.

Ill have to try tomorrow. I thought i had it and my oculus crashed. Rebooted and the drive was gone.

I just lost a 2nd hardrive.im 2 down of 5 and i dont trust my internal backup drive. And im afraid to boot my pc until i get an external drive to back everything up. Then i can see if im just unlucky. Or something is causing my drives to malfunction.

I fortunately have all the content i saved from the last drive death. And theres less import things on this drive. But ue4 was installed there...and my projects that i spent 2 hours getting everything reimpoted and stuff.

im having a very bad week.

[sphinix257]

ok i got lucky and i pulled the drive and ue4 wasnt on the drive like i thought. and i rewired the controlls from a fresh start, and i think i found the problem. if i flail my hands and click the run button rapidly, it bumps me a bit forward and stops. im useing a regular button input that i added. is it looking for a repeating input every tick to run the code correctly.

boom. i think i figured it out. i should have been using an axis mapping instead of a button press. i didnt know the difference untill now.
ive isolated the code out by its self. but for some reason it still only works when the movement mode is set. but i think i know how to fix that.

note: ill clean that up when i get it all working. thank you so far for the help.

edit: i got it. there was a movement mode check inside of CalculateRelativeVelocities. once i deleted it. it works all the time now. many thanks. now i can focus on a concept build, and get things moving again. ill shoot you a peak at it once its in a show able state. this plug in and all of its exsample codes are fantastic. albeit interwoven pretty tightly. alot for a new guy to wrap his head around.

edit: i see now what i had mistaken. i didnt understand "get relative velocitys for locomotion" because i never could find "CalculateRelativeVelocities" after that. all of it make perfect sence. and i can learn from it and figure out how to make use of it. thank you again for pointing me in the right direction.

[Parth Patel]

You grabbed the pre-compiled or the source?

I may have forgot to update the pre-compiled to a version that I fixed an Epic bug in that causes that assert (its not a crash). Its important if you are still getting it on a current source build though because it should be fixed, let me know which one.

I'll package up 4.19 to pre-compiled again though since I think it is missing the fix.

The bug is reported to Epic but I fixed it locally until then.

*Edit* Uploaded a current build to the pre-packed binaries

I downloaded latest pre-compiled version and it has fixed the issue. Thanks for quick fix and awesome plugin.

Thanks,

[mordentral]

Pushed some commits to the plugin, been a little slow due to constant sickness this flu season

 
 Fixed up inlines in the Motion Controller (PS4 support fixes). May  
 slightly decrease speed of the grip updates, but it is literally only two  
 non virtual function calls worth of difference so it is negligible.  
     
 Added bIsPaused to the grip structure and a SetGripPaused node to the motion controller.  
 Is not replicated by default (on purpose) as I felt that it is generally more useful  
 when additional data is passed through with it (snap location, ect.).     
 Added SetPausedTransform node to set the location of a paused grip (including a physics constraint if it is left on).   
 Expanded on SetGripPaused with additional options.

[GregFTW]

Hi!
First of all, thanks Mordentral for your hard work!
I have problem with simple physics enabled world objects. Is this expected behavior for player - actor collisions?
You can see here just a simple streched cube with physics enabled and few constraints.
I would like to achieve similar result to default FPS character, is it possible?
https://www.youtube.com/watch?v=FtWEKpVoPXw

[mordentral]

Hi!
First of all, thanks Mordentral for your hard work!
I have problem with simple physics enabled world objects. Is this expected behavior for player - actor collisions?
You can see here just a simple streched cube with physics enabled and few constraints.
I would like to achieve similar result to default FPS character, is it possible?
https://www.youtube.com/watch?v=FtWEKpVoPXw

By default I have the characters ignoring simulating objects in floor checks as it can toss player characters around wildly. Its a safety check and at this point is kind of less useful than when initially added.

Its a boolean option in the character movement component though, if you turn it off you should get default behavior.

    // If true will never count a physicsbody channel component as the floor, to prevent jitter / physics problems.
    // Make sure that you set simulating objects to the physics body channel if you want this to work correctly
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "VRMovement")
        bool bIgnoreSimulatingComponentsInFloorCheck;

[pixelvspixel]

Mordentral, do you have any thoughts about what to do if a physics heavy, VR experience needs to take place on a moving platform? I'm still trying to figure some options out, but it didn't really dawn on me what that might actually mean till I got deeper into my project. Of course something like a high-speed train sequence or a space ship could probably fake it by looping its background around the play area, but I'm trying to do more of a cable car sequence with a fairly expansive view.
I swear I've seen some VR train games like Derail Valley that had a physics sim on a vehicle that moved through the world. I'm just trying to figure out if I'm asking too much for a current gen system and I need to think about my experience differently.

Thanks for any insight you might have.

[sphinix257]

I dont think its to much for a current gen system. But in my opinion. it probably comes down to coding skill. It sounds really technical. But his template already has code for moving objects and you moving with them.

[mordentral]

Mordentral, do you have any thoughts about what to do if a physics heavy, VR experience needs to take place on a moving platform? I'm still trying to figure some options out, but it didn't really dawn on me what that might actually mean till I got deeper into my project. Of course something like a high-speed train sequence or a space ship could probably fake it by looping its background around the play area, but I'm trying to do more of a cable car sequence with a fairly expansive view.
I swear I've seen some VR train games like Derail Valley that had a physics sim on a vehicle that moved through the world. I'm just trying to figure out if I'm asking too much for a current gen system and I need to think about my experience differently.

Thanks for any insight you might have.

Well constraints are always going to be effected by momentum, so...say your train car were to turn left fairly fast, all constraint based grips or hanging lights (ect) would bounce as they would have a sudden change of force from forward to left/forward. This is actually fairly correct though? You would want constraints in relative space to the parent object and they wouldn't have a problem keeping up.

If you are talking about simulation objects being left behind...well you would likely have to impart the velocity on to them in order to keep their momentum correct, gets more complicated with sweeping turns and the like, fairly simple I would imagine on straight track, just AddImpulse for the velocity, however I can't see this being a quick method (cpu cost would inflate with number of simulating objects), so you would want to batch updates into a volume that gathers simulating objects inside of it and imparts the momentum to them at once, or you would want to force sleep objects that are an effective rest and attach them in place.

The character itself should be fine as it is based movement, grips for the character would need to be placed to tick after the base moves though so that they have the correct location, (IE: Base moves->character moves->grip moves), the default is already Character->Grip so you would have to add a tick req to the character for the base.


Outside of that there are a few options that are more complex:

1. Localized physics volumes (not default engine supported), possible but a lot of work.
2. Create a new physics scene separate from the main one and place objects in that, (not engine supported) fairly simple to achieve afaik, they already have an additional async scene for destructibles and objects that don't need to interact in gameplay, but would require engine source edits.
3. Fake it

There may be more options, I haven't tried to do something like this, its just off the top of my head.