VR Motion Cancellation - Time to test!

After some tinkering with “hardware rumble cancellation” I’ve almost satisfied with performance in Elite, it feels even better than with the Rift now.

There is one problem with Il2 still - it sends some random low-power jitter in flight, which doesn’t feel well, when augmented with motion cancellation - light chair movements translate to pretty bad trashing around of virtual cockpit.

What methods exist to filter them off on Simtools level?

Hi, I'm trying to get this to work with the HP Reverb and D-Box racing sim. It works perfectly if I test the platform while having SteamVR dash open, but it doesn't work in any of my sims! There, the tracking is shakey af. But it is perfectly still while looking at the SteamVR dashboard. Has anyone had this?

Tracking a WMR tracker mounted to the wall. On the rig won't work at all.

Thanks!

Needs to be on the rig or else it will turn itself off and it needs to be really highly isolated from the vibrations

What is this "hardware rumble cancellation" you speak of?

Tonight I got my first little test ride and I'm ready to start tuning so I'll be installing motion compensation hopefully tomorrow night and get a proper test of the zeal gel. Still have a ton of finishing work to do on the cosmetics though.

I tried my Gel packs I bought and they are rubbish to be frank Vibrations still getting through, the WMR controllers are so sensitive to it its impossible

The best way for me to get rid of the vibrations with the WMR controllers is to have it fastened down as hard and as tight as possible I just need to make some sort of design for the LED ring to hold it really secure and as tight as I can

Again....I think the best way to solve this will be to have the 6 DoF movement amounts (rotation and translation), calculated in Software, then fed into the OpenVR Input Emulator.
Both developers of HexPod and the Open VR Input Emulator say it is possible. The Input emulator Dev is going to build in the feed mechanism to receive the data. The HexPod dev is a little busy at the moment. But if the components can be developed, it will be a software approach that could work for almost any 6DoF platform, and no need for gel vibration absorbers, lighthouse trackers and any other physical paraphernalia associated with a mechanical approach to this problem.

Yes, that will be fantastic if it works. There are a couple potential problems that could prevent this from working, mostly latency. I think the only way to find out for sure is to try.

On a related note, I'm concerned about the possibility of Lighthouse going away with the next gen of VR. My Index should hold me over for a good couple years though. =D

Could anyone please elaborate a bit about the purpose of motion cancellation? Forgive me my stupidity but I can't quite understand the real benefit of it

Whole purpose of motion chair is to imitate g-forces associated with movement of simulated vehicle. Without motion cancellation in VR only thing it “imitates” is moving (or, to put it clearly, trashing about) chair inside that vehicle. Clearly not the thing most real-world vehicles are equipped with

Is it related only to motion chairs or also with full motion sim rigs?

Without motion cancellation, when your sim rig moves or tilts to a large degree to simulate the G-forces, you appear to move within VR also. i.e. When braking, your rig may pitch you forward which makes you feel like you're braking in real life, but the viewpoint in VR will tilt such that you end up looking at your virtual feet instead of through the windscreen.

@wonderin With normal seated VR, say in an aeroplane, your body does not move around relative to your seat in both the real world and in VR unless you move around deliberately right? For example standing up while flying a plane, you will move up in the cockpit and go through the roof.

Now with motion platforms imagine your platform is moving up and down 50cm with turbulence. Your body inside the VR cockpit will also move up and down that much, so it looks like you are standing up then sitting down.

With motion cancellation we want to keep our own deliberate moves (tilting head, looking up at instruments on the roof, looking out the window), but cancel out the translations of the moving platform, XYZ translation movements (eg turbulence) and XYZ rotation movements, (eg acceleration and braking)

HTH

@wonderin
To put it most simply, imagine you installed your motion sim inside your car in place of the drivers seat. Whatever movements it makes are moving you around inside the car. This is what happens in VR with no motion compensation. Motion compensation makes the "virtual car" move with the simulator movements so that you are always positioned in the car the way you are meant to be.

This might help you understand. How big a problem this all is depends on how much angle and/or displacement your motion simulator can produce.


Also, with 6DOF rigs the translational movements will move you around inside the car. You can wind up with the sim moving you back enough that your vision is obscured by the headrest of the seat being in front of you. If your 6DOF had enough range of motion you could wind up with your head outside the car even!

Ok, so I have finally got to using motion compensation again. I uninstalled SteamVR and started fresh, and used the info and download I recently linked here and had no problem whatsoever getting it set up.

I flew for a couple hours with the vive tracker and my shakers running and I got a little jitter once in a while but nothing serious. The following day, the tracker just kept getting lost. I never thought about this before, but my main problems have been with the POSITIONAL tracking getting screwed up, the x/y/z issues have never been a real problem for me. I thought that was pretty odd considering how the lighthouse tracking works... no reason for it.

Anyway I wanted to fly so I switched out the tracker for another (I bought one for each hand and one for the sim). It worked for a while then started the same crap.

Well... a page or two ago someone mentioned a rumor that the Vive wands have better tracking then the trackers. I swapped in a wand instead of the tracker and voila, so far it's been 100% since I did that. So... these damned pucks are total garbage. $100 bucks a piece I paid.... ouch. I'll have to check for updates on them, and I'll definitely be writing a politely worded but very unhappy email that HTC will totally ignore based on their reputation.

Did I understand correctly that motion compensation method (vive base stations outside sim, vive wands attached to seat and Open VR input emulator) result vibrations on picture? If so, how bad is it? I have currently RacingCube and Oculus rift and are thinking about switching to Valve Index if that works with motion cancellation (anyone tested it yet?). I just found Vive Pro full set 0n 850€ but don´t like that OLED panel SDE at all so would prefer Index if it Works and return the Vive. But if there is problem on all of them then I will be thinking to keep my oculus instead. Is it so that problems with making motion cancellation work at all are for Vive Trackers? Or does anyone have problems with Vive Wands too?

I switched from Oculus CV1 to OG Vive for exactly this reason and never looked back. With the superior SteamVR HMD's available now it's an even better proposition.

You may not get perfect results, but I consider the results pretty damned good and far better than any other currently available solution for VR on a high angle/displacement motion simulator. From what I've read the SDE isn't much different between Vive Pro and Index. Index has a screen with less SDE, but it has a larger FOV and therefore magnifies/stretches the pixels over a larger area and winds up being pretty comparable in terms of that issue. I don't know if you've tried the Pro (I haven't) but if you haven't tried any better HMD than Oculus CV1 you will probably be pretty happy. These new headsets certainly are not yet "perfect' but they are a rather large improvement IMO.

The Index is worth it for the clarity of the display and the amazing headphone speaker thingies. Text legibility is superb and the "sweet spot" is nearly the whole lens. The super high refresh rate really does make motion blur a thing of the past, and I've seen no ghosting. Super comfy too. Still lots of reflections/god rays in high contrast dark scenes though, and screen door effect is reduced to complaints that in brightish scenes you can still make out the pattern of the pixels and get some aliasing but I kinda disagree with calling it by that name any more. I can no longer focus on a single pixel, but I can still see them.

Possible new information on the Vive Trackers issues. I started doing some searching and found a post by HTC stating that the trackers misbehaving might be from "dirty" USB power.

I'm going to try the dongles in the clean power USB ports my mobo has, and also try the internal dedicated USB 3.0 card I have installed in my rig for VR.

Supposedly the reason the controllers might work perfectly and not the trackers is that the receivers in the HMD they connect to are getting clean power from the Vive/index dedicated power supply With the trackers we are generally using dongles, or permanently plugged into a non-clean USB port.

I will report back after I test the on-board options I have that could work. I do have the inateck internal USB card that is recommended by HTC for solving these type problems so I'll let you know if it works.

So at this point you’re using the Index, and you found that the Vive wands work well mounted to the seat, and you’re trying to get the trackers to work?

Just making sure I’m following you as I have the Index being delivered this week to replace my Pimax 5k+, and I currently have a tracker mounted to the seat.

And you have found that the Index with wand works well?

You should be fine, but the details are a little more complicated and my testing so far was very brief. Let me see if I can prevent this from becoming my usual wall of text. =P

I had some controller issues during my first (and so far only) test of Index with using the Vive wand for motion compensation but I don't expect any real lasting problem. I was rushing things and I think that I managed to cause SteamVR some confusion as a result.

I will just make a list of facts instead of writing a ten parapraph boring story:

• Vive Trackers frequently lost positional tracking, when used for motion compensation this frequently put me well outside the cockpit for seconds or minutes. I had always blamed these issues on vibration and/or EMI from my motion sim and shakers, but the other day it happened with the sim and shaker systems turned off which caused me to try a wand instead since someone here posted that there is a rumor the wands are more reliable or accurate than Trackers.

• Using Vive wand instead seemed to 100% fix the problem but I only got to test this for two hours or less. This test was done with OG Vive just before the Index arrived.

• I plugged in the index and paired the Knuckles and attempted to repeat the test flight I had just done with the Vive and I had controller issues. Knuckles system buttons would not work, but these issues disappeared as soon as I exited DCS World and played the Knuckles tutorial game and they have worked flawlessly since. I have not yet played with motion compensation or otherwise turned the Vive wand or tracker back on, I just played with the Knuckles in normal VR apps and games to try them out.

• I have since read that the tracker issues may be resolved by using a USB port for the SteamVR dongle(s) that provides "clean" power. I will try to go back to the Vive Tracker using this information as it's more conveniently sized/shaped for the job.

• I also want to use my other two Trackers for hand tracking, so I have more reason to wish to fix the Tracker problems beyond the size/shape of the Tracker vs. the wand.

• I did the thing in the SteamVR menus to delete all SteamVR device data and drivers to start fresh since at this point I had 2 wands, 2 Knuckles, an OG Vive, and three Trackers all registered. I then bound the Knuckles first and used them a bit, and will now bind only one additional device at a time and test before adding another just in case I have problems so I know exactly what change caused them.

Also @rsbell : Please report how you feel about going from the Pimax 5K to the Index. I agonized over the decision of which of those two to buy, and in the end went with the Index. I've never tried the 5K or 8K, the FOV is obviously very exciting but I feared compatibility/support/performance issues would be a problem at times. I figure there is no HMD less likely to have issues with SteamVR than Valve's own hardware. =) Anyway I'd like to hear how you feel about the differences between these two HMD's. I don't trust SweViver much, I feel like he's always going to say Pimax is best no matter what.