SlimeVR Full-Body Tracker
An affordable, comfortable, wireless, 360° solution for full-body tracking in virtual reality
SlimeVR is a set of open hardware sensors and open source software that facilitates full-body tracking (FBT) in virtual reality. With no base station required, SlimeVR makes wireless VR FBT affordable and comfortable.
SlimeVR FBT provides simple, effective tracking of your body and limbs in VR games and other applications. it makes full-body tracking comfortable and affordable by leveraging high-quality inertial measurement unit (IMU) sensors and a Wi-Fi connection to your PC rather than wires, cameras, or base stations. Taking the Lower-body set as an example, five trackers—one on each thigh, another on each ankle, and a fifth at the chest—are enough to get the job done. Each tracker monitors its own rotation in space, and SlimeVR software uses your proportions and headset location to calculate joint angles and estimate limb positions. In more technical terms, SlimeVR relies on absolute-orientation sensors, a configurable skeleton model, and forward kinematics. The result is like having virtual Vive trackers at key locations on your body.
The base set of five trackers is sufficient to cover lower-body movement (legs and waist) and is widely supported by VR games and applications. VRChat, NeosVR and LIV can use additional SlimeVR trackers to monitor the position and rotation of your feet, knees, elbows, chest, and more!
Your comfort is our primary goal. SlimeVR trackers are lightweight, easy to wear, and entirely self-contained. Because they do not depend on cameras or base stations, they are able to track a wide range of motion without ever being occluded, or blocked from view, in a way that would cause external sensors to lose track of them.
SlimeVR is broadly supported by popular VR software, including:
And much more as we grow!
Support for Full-Body Tracking depends on the game and its developers. Currently, only VRChat and VRWorkout support Full-Body Tracking with SlimeVR on Oculus Quest without the need to run the game on a PC.
Full support of this is still in development, but thanks to the recent updates from VRChat, where they introduced OSCTrackers, it’s now possible to use SlimeVR fully standalone with VRChat! Here’s a guide from TheMysticle that shows the set up process. Important note: We are still working on Android and Quest app for SlimeVR, so for now it requires using a terminal emulator to run, but we plan to solve it soon!
SlimeVR is not affected by magnetic interference or positional drift, despite its reliance on IMU sensors for tracking. Each tracker only monitors its own rotation, which is enough for our software to estimate your pose. That means your virtual legs will never do that thing where they suddenly fly away. (So embarrassing…) SlimeVR is also unaffected by magnets or metal, as it does not rely on a magnetometer. Over time, there is some horizontal-rotation (yaw) drift, so body parts can end up facing the wrong direction after a while. We’ve done a lot of work to compensate for this, however, and it typically takes between 20 minutes and two hours, depending on your activity, for any drift to become apparent. And if it does become apparent, don’t worry. Sensor recalibration is incredibly user friendly. In order to fix any drift issues that might arise, all you have to do is hold a straight pose while pressing a single button.
| SlimeVR | Vive | Tundra | AprilTag | Amethyst | HaritoraX | mocopi | |
|---|---|---|---|---|---|---|---|
| Developer | SlimeVR | HTC | Tundra | Ju1ce, DIY | K2VR Team | Shiftall | Sony |
| Form factor | 5x 50 g trackers | 3x 75 g trackers | 3x 50 g trackers | QR codes & central camera | Central camera | 5 trackers connected by wires | 6x 8g trackers |
| Battery Life | 15 h | 7.5 h | 7 h | ∞ | ∞ | 10 h | 10 h |
| Base station | No (Wi-Fi) | SteamVR Lighthouse | SteamVR Lighthouse | Any camera | Kinect | No (Bluetooth) | No (Bluetooth) |
| Prone to occlusion | No | Yes | Yes | Yes | Yes | No | No |
| Coverage | 360° | 360° | 360° | 360° ² | 360° | 360° | 360° |
| Precision | 1-10 cm ¹ | < 1 mm | < 1 mm | < 1 cm | 1-10 cm | 1-10 cm ¹ | 1-20 cm |
| Latency | ~15 ms | ~15 ms | ~15 ms | 30+ ms | ~20 ms | >15 ms | 50+ ms |
| Update rate | 100 Hz | 90-144 Hz | 90-144 Hz | Camera framerate | 30 Hz | 50-100 Hz | 50 Hz |
| Range | Wi-Fi coverage | 10 m | 10 m | 2-3 m | 2-4 m | Bluetooth coverage | Bluetooth coverage |
| Can track any object | No | Yes | Yes | Yes | No | No | No |
| Open Source | SW + HW | No | No | SW + HW | SW | No | No |
| Price | $195 | $390 + ~$400 Lighthouse | $360 + ~$400 Lighthouse | Printer & camera | ~$30 (used Kinect) | $299 | $450 |
¹ The precision of SlimeVR and HaritoraX tracking technology depends on your setup, on the plane used for measurement, and on how your back bends.
² AprilTag requires additional waist tracker with a phone or other tracking technology (has reliable 180° coverage without).
The base set of five trackers is sufficient to cover lower-body movement (legs and waist) and is widely supported by VR games and applications. However, with SlimeVR you can customise your experience in VRChat, NeosVR and LIV to track specific movements, allowing you to finely track the bones you want with additional trackers allowing you to track feet, knees, elbows, chest and more!
Tracker Extensions are smaller, auxiliary trackers without batteries or Wi-Fi capability. They connect to a primary tracker by means of a wire and provide a simple, comfortable way to add additional tracking points.
The table below illustrates how different sets of SlimeVR trackers can be used in games and software games and software that support 11-point tracking (like VRChat, NeosVR or LIV) or six-point tracking (Blade and Sorcery and some other games). It’s possible to change the layout and focus on what you’d need more, for example, attaching trackers to elbows instead of feet. SlimeVR can also partially mix and match with other tracking systems, like tracking lower body with Vive trackers and elbows with SlimeVR.
| Set | Primary trackers | Extensions | For 11-point tracking (VRChat, NeosVR, LIV) | For six-point tracking (B&S and others) | Price |
|---|---|---|---|---|---|
| Lower-Body Set | 5 | 0 | Waist position & rotation, foot position, knee position & rotation | Waist position & rotation, foot position | $195 |
| Core Set | 5 | 1 | Waist position & rotation with increased precision¹, foot position, knee position & rotation, chest position & rotation | Waist position & rotation with increased precision¹, foot position | $225 |
| Enhanced Core Set | 5 | 3 | Waist position & rotation with increased precision¹, foot position & rotation, knee position & rotation, chest position & rotation | Waist position & rotation with increased precision¹, foot position & rotation | $275 |
| Full-Body Set | 7 | 3 | Waist position & rotation with increased precision¹, foot position & rotation, knee position & rotation, chest position & rotation, elbow position & rotation | Waist position & rotation with increased precision¹, foot position & rotation | $350 |
| Deluxe Tracker Set | 10 | 6 | A future-proof tracker set for the VR obsessed – with capabilities at least equivalent to the set above, plus a little something extra for motion capture, experimentation, and imagination. | Waist position & rotation with increased precision¹, foot position & rotation | $560 |
¹ Hip tracker extension improves spine tracking, which greatly increases precision while sitting or bending, especially in extreme poses.
Below is a video by ZRock35 that showcases tracking with different SlimeVR sets. It’s also a good demo of how much better the tracking has become since the campaign started!
SlimeVR is open hardware driven by open source software and is released under permissive MIT & Apache 2.0 licenses. This open design empowers the VR community to expand on the SlimeVR ecosystem, create new devices, add compatibility with new software, and improve upon all aspects of the project. For our part, we are focused on helping that community expand SlimeVR infrastructure by adding support for various devices, protocols, and features. We are part of an active DIY community, members of which build their own SlimeVR trackers, help others get into DIY electronics, contribute to our documentation, and develop hardware with different features and at different price points. All of our hardware is hacker friendly, and we encourage you to use it in new ways and adapt it to your needs! You can find documentation about our DIY kits on our website!
Our open source software and firmware is in our GitHub repository. We have guides and schematics for easy DIY and are working with the community to make them better, more accessible, and compatible with a wide range of hardware and tools.
More specifically, our documentation is here, and our GitHub repository contains:
The official hardware design is hosted on OSHWLab:
Join our community on Discord to meet other VR hackers or to chat about SlimeVR. You can also find us on YouTube. And, if you have a question for our team, you can reach out using the Ask a technical question link below.
SlimeVR includes 2-year manufacturer’s warranty. The warranty starts on the day when you receive your products. For any warranty-related questions and claims, visit our Contact Page or use the Ask a technical question link below.
Production SlimeVR PCBs are fabricated and assembled by LZJ PCB, a contract manufacturer with whom we have been working for multiple years. IMU modules are produced by AssemTec Europe. Each board is tested at their factory and by us after the final assembly. ICOMold is handling injection molding for the tracker cases, and the final assembly is done by our team and an assembly company in the Netherlands.
After the SlimeVR hardware is manufactured, it is sent to Crowd Supply’s fulfillment partner, Mouser Electronics, who distributes it to backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.
SlimeVR has faced many challenges during the manufacturing and fulfillment, and some of them are still ongoing. But thousands of our backers already received their sets and happily use them, as well as dozens of YouTube reviewers, and thousands of members of our DIY community. It’s always possible that new challenges will emerge, but our team is determined and experienced to solve them.
"This is the CHEAPEST full body tracking I’ve covered on my channel yet! Slime VR is a complete game changer considering you DON’T need base stations. "
"Low-cost body tracking pucks require no cameras or base stations, and the software and firmware are both permissively licensed."
"This is Full Body Tracking for virtual reality that is for everyone. "
Produced by SlimeVR in Rotterdam, the Netherlands.
Sold and shipped by Crowd Supply.
Five SlimeVR trackers, enough to track the position and rotation of your waist and your knees, as well as the position of your feet. Includes five straps and one USB Type-C cable.
Five SlimeVR Trackers and one Tracker Extension, enough to track the position and rotation of your waist (with improved precision), your knees, and your chest, as well as the position of your feet. Includes six straps and one USB Type-C cable.
Five SlimeVR Trackers and three Tracker Extensions, enough to track the position and rotation of your waist (with improved precision), your knees, your chest, and your feet. Includes eight straps and one USB Type-C cable.
Seven SlimeVR Trackers and three Tracker Extensions, enough to track the position and rotation of your waist (with improved precision), your knees, your feet, your chest, and your elbows. Includes 10 straps and one USB Type-C cable.
10 SlimeVR Trackers and six Tracker Extensions, enough to track the position and rotation of your waist (with improved precision), your knees, your chest, your feet, and your elbows – with enough left over to experiment with motion capture and other innovations. Includes 16 straps and one USB Type-C cable.
Seven DIY SlimeVR Tracker boards and three Tracker Extension boards, enough to track the position and rotation of your waist (with improved precision), your knees, your chest, your feet, and your elbows. This DIY kit includes only the boards and connecting wires for the Tracker Extensions. It does not come with enclosures, straps, batteries, or other accessories.
A small company enthusiastically pursuing the goal of bringing accessible VR to a wide audience.
