Valve's Lighthouse: Past, Present, and Future 

This is my favorite video of yours. Lighthouse tracking has always been so fascinating. Thanks for the vid brad :D

19:30 That was this sounds is that we might be able to get a "seamless" hybrid tracking system, where you *can* have base stations where you want high accuracy, but it also functions without base stations in a lower quality inside out mode. As much as I lament how unportable the index is, the incredible tracking quality is something I can't give up, and this system seems like the perfect compromise.

Can't wait for the Lighthouse 2.0: Episode 1, to release!

The 2.0 stations are fascinating, but in a way, it compromises reliability for higher convenience, which I'd argue makes them more inconvenient over 1.0s, but if you have 3 or more stations, that doesn't matter because you never had a choice. From my experience, the 1.0 stations always provided outstanding tracking performance and do have an upper hand on the 2.0s because 1.0s given their greater simplicity in the tracking system, provides better performance against reflections. I have weird tracking quirks with my 2.0s that I never experienced with my 1.0s and it's because of a few small pieces of furniture in my room that messes with the tracking. With a 1.0, you're only worrying with one laser sweep at a time where 2.0s are transmitting, channel data and such, which makes it far more susceptible to tracking issues if you introduce a slightly reflective surface in the play space. The 1.0s in my opinion don't get the credit they deserve because they are outstanding stations if you're looking for a lighthouse system, are on a budget and don't plan to use more than two stations. I see Quest users buying 2.0 stations all the time and I scratch my head over it because 1.0s would have done the job just as well, at a cheaper cost. I rate 1.0s.

This was a great overview! I would love to see more content about things like this. I think it can really help the community not only appreciate the technology we currently have more, but also understand the challenges that developers have to move forward.

The thing at 16:00 is most likely a so called 'PSD' aka. Position Sensitive Device, used in precision laser tracking metrology applications. I have worked with those for the last 15+ years. It most likely boils down to having lighthouses without rotors, but rather fixed wide angle laser cones. Removing moving parts greatly reduces wear and acoustic noise. The PSD would be behind a small wide anlge 'fish eye' lens, being able to 'see' from which direction the light comes in. Several of those dispersed over the exterior like the classical photodiodes would allow for parallax/perspective/triangulation/trilateration, which is necessary for rangefinding. The individual emitters would need precise timing amongst them since a single PSD only works well if hit by one light source.

If they can get rid of the motor and make a solid-state base station system, especially if the base stations themselves can become smaller and lighter in the process (even the 2.0s are still kinda heavy), it will be a game changer. I'm glad to see Valve continuing to push the idea forward instead of giving up and using camera tracking like everyone else.

Lighthouse Alyx

It's nice to hear that Alan Yates is still at Valve. I was wondering what his current projects are

That quad photodiode reminded me of how early Philips single-beam CD players achieved tracking by measuring a shift between 4 cells. This is just additional info about focusing for those who care. For focusing CD players use a cylindrical lens just before the photodiodes that distorts the beam when it isn't in focus. If it's out of focus one way, cells A and C will receive more light than cells B and D, and vice versa; this will send either a + or - voltage to the focus coils to move the lens up or down to compensate. But when focus is perfect, a circle will form, and all A, B, C, and D cells will receive the same amount of light. Haven't fixed a CD player in over 10 years, but that's what I remember from the theory lol.

I love lighthouses and hope they can provide full body tracking too

Some of the arcade games I have repaired have used that same quad photodiode for gun/aim tracking, such as Jurassic Park Lost World. Another arcade game, Rabbids in Hollywood, actually uses the sixense electromagnet tracking system for their guns. I wonder if that tech will ever find a place in VR since the fall through with oculus.

This imply there's a heavymansion tracking somewhere out there

Been using Logitech trackballs for 15+ years. Glad to see someone else realizing their potential. FYI you can get a 3D printed stand for the Ergo+ to raise it to 60 degrees

Those quad photodiodes are very similar to what's in a CD player (and DVD and Blu-ray) it can be used to sense if the reflected laser off the disc is in focus and centered. So it's possible that Valve has repurposed a diode design that's complex but still extremely cheap because they're been making them since the 80s.

The angle sensitive photodiodes + the light scatter detector is a big improvement. More accuracy, and less reflection effect from shiny objects.

Thank you for that detailed explanation of how light houses work. Very interesting.

Been using lighthouse since days of Vive Pre, still using lighthouse today. Steamworks dev here with several years of experience building prototype steamVR controllers, thoroughly enjoyed your video and collection of historical pieces Keep doing what you are doing it's very welcome 🍰

I think the most important thing you may have overlooked is that by using polirized light filter, they would also elimanate the reflection issues with this system. Mirrors, reflective floor and object would be less of an issue. Thats so far the biggest downside for the lighthouse system, something at which visual systems are a lot better actually.

I've always wondered how those things worked. This was super informative, thank you for going over this. I always love learning more about VR tech from your videos

Oh nice! been waiting for this video to drop 👍

Thanks for this. So helpful to get some insights into how the tech works.

Love it, thanks Brad!

Top work. Very informative

I am a little surprised you didn't mention that the most significant advantage of making the controllers mini lighthouses is that you would then need only a single base station for the whole setup to work. Especially if you put diodes all the way around the headset. Another advantage that should be mentioned is that by making the diodes able to sense the directionality of the laser pulse, you make the system way more flexible. For instance, the original lighthouses were limited on where to put them in the room. These would not be like that at all. Where you positioned them would be a lot more flexible. Lastly, I would be shocked if they didn't make this new base station double as a wifi 7 router that must be plugged into your computer. Allowing for a single lighthouse that could act as both your positioning system and your communication hub to stream the games from your PC.

good one Brad, good work, good description, good job....

It is pretty freaking cool man. It's wild the layers and layers that goes into all this. Awesome video man, really top-notch work. This is the kind of thing I love to know about.

Thank you for another video brad ;3

I assume like everyone else I was watching this thinking - "please, Brad, tell me that my 5 expensive base stations won't be obsolete by the end of the year!??"

I was able to use 4 HTC vives on the same space at events, the trick was using just 2 base stations pointing in the same direction synced with the cable.

Brad, that was a great video! I learned so much! Thank you!

Great video! Very informative

Appreciate the long video. Your passion really shows through and it gets me excited too! 😃

Love this video, very facilitating

very important for understanding the Valve Lighthouses - many many thanks - Brad + all the best the next months + more

Stellar video, fascinating content!!

Very interesting, another great video.

The worst thing I hear from some people about lighthouses is when they refer to them as "sensors", while they are actually emitters. Technically speaking, the Valve Index is actually inside-out tracked.

💚Fascinating work Brad! Thanks for breaking down this highly technical discussion, you are a master at it!

Great video Brad, I thought I knew how the light house system functioned, but you are on another level 🙇‍♀️

Damn finally know wtf those things are actually doing. The term "lighthouse" makes a lot more sense now.

Super interesting stuff, thanks for sharing. I always found the lighthouse technology fascinating!

I knew that lighthouses had rotating parts but man is this technology mindblowingly fascinating. Somehow I find it more fascinating than SLaM tracking even though SLaM is more technically difficult to achieve.

This was a good explanation of how lighthouse tracking works, i learned a good bit, thanks

Fresh coffee and a fresh Brad video. Day made.

Interesting, cool to hear about this tech

Dope video:D

loved this video, really interesting uwu thanks

super cool

This explains the Lighthouse revisions really well. I understand now- my brain is slightly more wrinkled.

That was such a good engineering candy. Thank you very much!

Great video thanks👍

As a life time track ball user I agree they are amazing .

logged into google just to praise your video with a thumbs up! this was a great rush through lighthouse history. only complaint: you did not show the internals of the basestation 2. anyway, please make more such more technical videos! THANK YOU!

thank you for this

I enjoyed this video very much. Color me a fan of lighthouse tracking.

Yum. More info. You posted this 6 minutes ago and it's Overr 20 minutes long, so I hope to hear you talk about how the basestations used harvested 15,000rpm motors from Seagate cheetah drives!

I love lighthouses. I hope they never die.

22:42 Yep, thanks for explaining.

LH tracking is my favorite high speed and accurate tracking method. I also love my LH v1 ones since they are the most high tech I own.

Brilliant!! Thank you! I currently use a modded Samsung Odessey +. The next Valve VR helmet is exactly what I am waiting for unless HP comes out with an OLED version of the G2.

i tried 1.0 and 2.0. i love it both ❤

I've been using trackballs for over 13 years. I even use the the trackball mouse on laptops!!!

I want more Pappy Bradley vr history fun time!

Would be interesting to see Meta price match Vision Pro and show us what they can do with the same price point. Varifocal lenses, wider fov, battery life, theres a lot of features Vision Pro is still 'missing' they could capitalize on.

I understand a bit better why I want to upgrade from my 1.0s on my walls now haha Great video, awesome to understand what's going on under the hood.

I've known about the Lighthouse technology, probably at least in part because of Brad, since long before upgrading to the Index, but this was still an interesting video to watch.

Anyone who played bow and arrow games, or billiards games (eg Sportbar VR) knows how essential lighthouse tracking is for finding the controller behind your head or next to your head. The only way I see inside out working is if the controllers have cameras to track themselves in 3D space.

Thanks for sharing. I am still patiently waiting for Valve Deckard even though I probably should just get Index and start playing...

Honestly, I had been thinking, if there was a way to improve upon tracking as well, came across your video all because of some lingering thoughts I had about "what if some individuals managed to crack an even better or improved tracking solution to the lighthouses". I honestly would be more than hyped to hear if people were creating more reliable 3rd party lighthouses kind of like how we have these headsets and trackers. It's just something I love about what the community and Valve have, this opensource world is just so much more better, and also enables more curious individuals to take a shot at making some new technology... Unlike facebook which I officially will call the IOI of our world from now on XD

I still use LH1.0 with cable. My LH mounting points are not optimal for that IR link because they need to have unrestricted line of sight. Basically I had to mount them too low but cable was enough long to be routed down the floor and I didn't need to make shortcuts. Only one problem was my ceiling light that I needed to change to non reflective material one. Older light did reflection of one lighthouse so I have about cone from that light through play space where headset and controllers go crazy.

I'd really like maybe a wifi tracking thing like Slime, so you can occlude them, but it uses the moments it sees a base station to reconfirm its positioning and calibrate

Always love looking at my basestations through the quest 2. You can see it spinning.

I see "Valve" and i insta click. Thanks for keeping us informed :)

been waiting for a Lighthouse 3.0 for a while now. It is cumbersome and expensive, but for millimetrical precision... don't know what else could be better. Guess that, combined with a tracking suit... if you aint a plebe :(

I just sent back a Valve basestation 2.0 because it was jittering. Seems like a common problem especially with the 8KX if you have a motion-rig with actuators causing some sort of EMI (electromagnetic interference) and even using four stations doesn't solve it. Two basestation 1.0 work btw. and probably the reason why they are still quite expensive if you buy used ones.

Frickin' laser beams! As much as there's cool technology on the receiving end, I'm sort of amazed that there isn't an "electronic", "variable polarizer based" or "solid state" solution (I'm using quotes because I'm just pulling science words and I don't really know) for the base station that would get rid of the spinny mirrors.

It is really nice to show them running with a camera without IR filter, but it is actually not good for the rotor to be moved while spun up, especially if of rotate the boxes, as the gyroscopic forces can added much more force on the bearings than normal gravity. The manual also warns against moving them while spinning. Alan Yates actually said they even have sensors to detect such disturbance and turn of the laser, so better to transmit not at all than to transmit bad information. You can actually see the laser turning off from your hand movement sometimes.

That giant cable between the base stations was still some of the best tracking for me

Wow video is shot using HDR and it looks so good on mini led iPad! Bright colors are almost blinding you!

I've been a trackball fan boy for decades.

I do always wonder the tech behind that little black box, now I know and appreciate it more. Thanks

IT's BRAD

That was super interesting, I find it realy cool to finaly understand the base station better... I know that Meta have kill there good old traking system that was used with the old Oculus rift, but I am curious to know what was the big difference betwen the 2 method.... I kind of feel this thechnology was having also a lot of potential, specialy on the enegy cost, went a controler could survive month of use on a signe AA battery

Awwww thanks for the shout-out to both the companies I'm involved with. Tundra and Triad. TnT. Lol

With the Quest 2 passthrough you can see the light emitted from the base stations. They also enable you to play your Quest 2 in the dark (if your using the Quest controllers)

Would love a video on what you think AI means for VR Brad. Love your work mate.

I'm gonna go look at my base stations and the room while they're on with my IR camera now. I don't know why I never thought of that before, I knew they were "laser based" and since I can't see them that means they pretty much have to be IR.

Thanks for the informative video. It is very interesting. I rather see the future in inside-out racking systems. Wouldn't it be effective to use depth sensors for tracking? Is there any development in this direction?

This was so interesting! Thank you for explaining so much about lighthouses. But i am still waiting for the day when you leak that valve is starting the mass production of their new headset T.T ❤

23 minutes! let's fucking gooooo!

you could use photo diode to track the controllers with ir lights coming from the like the quest but not with cameras seeing them. also have accelerometers so that atleast it has a rough position of where the controller is when outside the headset field of view. then do head tracking with cameras backed up by an accelerometer and gyroscope.

Interesting topic. I've been interested to look into how tracking works. You mentioned right at the end that you like having a high resolution headset on and browsing the web on an overlay while in vrchat. Could you expand on how you do this? Right now I'm using immersed to have my computer screens augmented where I want in real life while I can be in a virtual environment, but I didn't know you can have your computer screen shown in vrchat. My guess is that you are doing this with OVR toolkit? So you run vrchat and in the background you get OVR toolkit to put the computer screens around you?

If I had to choice to hang up or stand up fewer tracking systems in a room verses putting on a tracking suit, I would choose the lighthouse style.

Cool! Dev of the kennect (Xbox) would be interesting too!😊

An ideal would probably be a visual + IR camera based SLAM tracking with self-referencing IR photodiode tracking through a mesh of sensors strapped to your body. Best in class motion tracking + no need for external reference as it's self-referential. One issue would be drift when you cover them up and can't "see" the other sensors, but it shouldn't be nearly as bad overtime thanks to the cameras. No change in scene? No relative motion for the sensor. Seems rather expensive, extremely high compute cost, and power hungry. But I personally think that's end game for consumer VR tracking.

I always wondered how the valve's lighthouse works... now I know, and it is freakin' cool, laser beams! :)

Im a huge fan of 1.0 lighthouses They are so freaking reliable but might not be optimal if i ever did full body tracking..

Good video, I like the detailed chapters so I can skip the old stuff, and lack of annoying sponsored segments. Please don't upload in HDR for videos that don't need it though. On my Pixel at least it forces the brightness/color to follow your video's mastering, meaning if i am in a dark room or have my phone set at low brightness the video is super bright and vibrant compared to everything else.

I've been using my 1.0 Lighthouses since I got them in the OG Vive I bought off a VRC friend last year just for my FBT on my quest 2, I was using the Vive but then the cable died a few months later. And I will still be using them when I get an Index because I can save a bit of money and they still work perfectly well.