[Move.ai] Technical Director Reviews Motion Capture at a Glance #2
The motion capture system we will be featuring in the second installment of BASSDRUM's Motion Capture Review is "Move.ai," an AI-based motion capture system that was released in March 2023 and has become very topical due to the recent AI boom.
In this series, we will be reviewing from the perspective of a technical director, based on the following criteria:
Let's get started!
*Note: We conducted our tests using both iPhone 8 and iPhone 12. *All information in this article is as of April 2023. (Test date: February 24, 2023)
Product Overview:
Move.ai is an innovative technology that enables markerless, high-precision motion capture using AI technology, and has recently garnered a lot of attention. (Refer to the official website)
By utilizing the camera of a standard smartphone and AI technology, it enables the reproduction of body motion through high-precision data collection in any environment.
Furthermore, without the need for special suits or markers, a simple setup and user-friendly UI allow a wide range of users from professional animators to beginners to use it.
Move.ai is used in fields such as film and game production, AR/VR content development, and sports analysis.
Compatible Devices:
Host: iPhone 8-14, iPad
Camera: iPhone 8-14
Supported Systems: iOS 16 or higher
Download Link: https://apps.apple.com/us/app/move-ai/id1642699132
Official Website: https://www.move.ai
Usage:
There is a tutorial video in Move.ai's official documentation. Please refer to it.
The operation procedure is as follows:
Check the preparation for shooting
Set up the app and camera
Perform calibration
Carry out the actual shooting
Upload the shot reel
Process the data
Handle the calibration
Process the actual shooting
Download the processed model data
Overall Rating
Accuracy: ★★★★☆
Latency: ——
Ease of Use: ★★★★★
Integration with Other Software: ——
Price: ★★★★★
Advantages:
Quite inexpensive as a motion capture solution.
Easy to set up. High precision cameras are not required, you can record with just an iPhone.
No suits or markers needed, recording can be done anytime, anywhere.
Extensive official support (guides on the app, official tutorial videos, official documentation).
Disadvantages:
Not usable in real time as of now.
Lacks a bit of precision. However, this can be somewhat improved by increasing the number of cameras.
Recording and data processing cannot be contained in a single device, and operation of both a smartphone and computer is necessary.
There's a possibility that the data upload may get interrupted and fail. If it fails, you need to restart from the initial calibration.
This service could be perfect for those who "don't need to use it in real time and want to create content using 3D", "want to try motion capture", or "want to use an affordable motion capture".
Here are the details for each item!
Accuracy ★★★★☆
First, please take a look at the footage of BASSDRUM's members testing Move.ai. The movements tested this time are as follows:
Raising Arms in Celebration
Crossing Arms
Box Step
Jump
Sitting on the Floor (cross-legged)
Sitting on the Floor (gymnastics sit)
Sitting on the Floor (formal Japanese sitting)
Chair Sitting (from standing to sitting, and sitting to standing)
The jumps and chair sitting movements are reflected without any issues. However, it tends to struggle with poses where body parts overlap, such as crossing arms and sitting on the floor. As reflected in the testing footage, overlapping body parts can cause deviations or positional shifts from the actor's movements.
Overall, it cannot be said that the accuracy is extremely high. This may be due to the fact that we used only two cameras in this test. The AI automatically completes movements in areas not visible to the camera, leading to somewhat unnatural or incorrect movements. It is believed that the accuracy can be improved by eliminating the blind spots in AI calculations and increasing the number of cameras to shoot from various angles.
Below is a comparison video with mainstream motion capture systems, posted on the official site. From this video, there are no significant differences when compared to other motion capture systems, and the high accuracy of Move.ai is evident.
Move.ai vs OptiTrack:
Move.ai vs rokoko:
Move.ai vs Movella MVN Animate (formerly Xsens):
Move.ai vs vicon:
Latency
Not rated yet
At the present time, it is not possible to use this in real-time. However, according to Move.ai's official Twitter, they have announced a partnership with the media server company "disguise" to develop a real-time motion capture solution. The release date is still undecided, but we can look forward to a more advanced real-time version of Move.ai in the future.
Real-time markerless motion capture goes live!!
Please take a look at how Move.ai works with its implemented real-time motion capture feature.
RealTime markerless/suitless #mocap demo
In the demo video, you can notice a slight delay. However, considering it's doing real-time pose estimation and video output, this delay might be within an acceptable range.
Ease of Use ★★★★★
Required equipment:
An iOS 16 or above system device (1 host, at least 2 cameras)
For higher accuracy, 4-5 cameras are recommended
Tripods (the number required varies with the number of cameras)
Required personnel (including actors): 1 person
Time to setup (until motion capture is possible):
About 5 minutes
Device setup: 4 minutes
Determining the shooting range: 30 seconds
Calibration: 30 seconds
Minimum space requirements:
Varies depending on the number of cameras used and the number of people being shot
If it's for one person, a minimum of 2m x 2m space is necessary
Move.ai stands out for its ease of use, as it eliminates the need for cumbersome suits and markers, doesn't require specialized shooting equipment, and allows for easy calibration. Additionally, data processing requires minimal operation, and the user is notified by email when it's finished, making the process less tedious. However, regarding the output, it took about 10 minutes to analyze 1.5 minutes of video. It appears there is room for improvement in analysis speed.
Integration with Other Software
No rating available
At present, real-time integration with other software is not possible. However, the generated motion data can be output as .fbx files and can be used with other software.
Price ★★★★★
App itself is free
Service usage fee is 365USD/year*1
New users get 2 minutes of motion capture for free
Maximum motion processing time per month is 30 minutes
Cost for exceeding 30 minutes is 0.04USD/second*2
Running cost: None
Commercial/profit purposes allowed
*1. As of April 12, 2023, approximately 48,880 JPY
*2. As of April 12, 2023, approximately 5.36 JPY
Compared to other motion capture devices, Move.ai is a significantly more affordable service. Furthermore, due to the subscription model, it is easy to unsubscribe without worrying about disposal of equipment, if you decide to switch to another service.
Other notes
In experimental mode, you can process videos shot with cameras or smartphones. This means that you can do motion capture of videos shot with any camera, without needing the app or an iPhone. However, there are the following restrictions:
The length of the video is limited to a maximum of 5 minutes per clip
Supported file formats are .mp4, .mov, .avi
There are naming rules for file names
Calibration video is required
You can record the movements of up to 8 people at the same time.
In experimental mode, it's possible to record up to 25 people.
From the above video, we can see that it is possible to capture the simultaneous movements of multiple people (9 people). Recording a large number of people may result in slightly lower accuracy compared to recording one person, but it is suitable for motion capture of 2-3 people. In particular, it can greatly save time when recording scenes where two people interact in movies or animations.
In conclusion
How did you find Move.ai, which boasts the charm of being "convenient and inexpensive"? Although Move.ai, which has just been released, boasts a very high accuracy among inexpensive motion capture systems, it is still evolving. With the advancement of AI technology, a revolution may be taking place in the motion capture industry, and we may be getting closer to a future of digital democratization where anyone can easily create 3D models. New users have 2 minutes of free usage time, so please give it a try!
That's all for the second motion capture review, "Move.ai". In the next installment, we will be reviewing the staple of motion capture, "Vicon"! Look forward to it!