> For the complete documentation index, see [llms.txt](https://help.onform.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.onform.com/sports/golf-analysis/model-card.md). # About Onform's 3D model What Onform's golf 3D model estimates from one video, how accurate it is, what affects results and where your video is processed. Onform's 3D model turns a single golf swing video into a 3D skeleton of the golfer, with body measurements at every frame. This page sums up what it estimates, how accurate it is and where it works best. The full technical details are in the [Onform 3D golf swing model card](https://onform.com/wp-content/uploads/2026/04/Onform-3D-Golf-Swing-Pose-Estimation-Model_Apr-13-2026-v2.pdf) (PDF, version 2, April 13, 2026). ## What the model estimates | Output | What it is | Needs | | ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- | | 3D skeleton | The position of the golfer's joints in 3D, frame by frame, shown as a skeleton or avatar you can turn and view from any side. | A face-on or down-the-line full swing. | | Body metrics | Turns, bends, sway, thrust and lift of the torso and pelvis, X-Factor and tempo. See the [body metrics glossary](/sports/golf-analysis/using-3d-data-and-visualization.md#body-metrics-glossary). | A face-on swing. | | Kinematic sequence | How fast the pelvis, torso, arms and club rotate through the swing. See [Read a kinematic sequence](/sports/golf-analysis/beginners-guide-to-kinematic-sequence.md). | A face-on swing, with the club head in the picture throughout. | | Swing positions | Address, the top, impact and other positions, found automatically. | A complete full swing. | | Club path and swing plane | The path of the club head, and the swing plane drawn from it. | The club head in the picture throughout. The swing plane needs a down-the-line swing. | ## Accuracy Onform has tested the model against lab motion-capture systems, including GEARS, OptiTrack, Qualisys and electromagnetic systems. Its results are generally within a few degrees for rotations and within a few percent for movements such as sway and lift. The model card has the full comparison. Some things are less precise: * **Club speed** in the kinematic sequence is estimated from a flat video, so it's less precise than the body lines. * **Swing positions** are found automatically and can be a frame or two off. * **Body metrics from down-the-line swings** aren't shown yet, because they don't meet the same accuracy bar as face-on. ## What affects the results | Factor | Best results | | --------------- | ---------------------------------------------------------------------------------------------------- | | Frame rate | 120 fps or higher. Below that, 3D isn't made. | | Length | Under 15 seconds, trimmed to the swing. | | Camera angle | Face-on or down-the-line, square to the golfer at about hip height. Behind or overhead doesn't work. | | Framing | The whole golfer in the picture from address to finish, at least half the height of the picture. | | Other people | None nearby. Onform follows the biggest person in the picture. | | Swing | A full swing. Practice swings, partial swings, chips and putts aren't supported. | | Light | Good, even light, so the video isn't blurry. | | Golfer's height | Set in the metrics profile, so sway, thrust and lift are scaled right. | | Handedness | Right- and left-handed golfers both work: Onform works out which way the golfer faces. | | Recording | Recorded in Onform, or imported with its frame rate intact. | ## Reference ranges Reference ranges color the body metrics green, orange or red to compare a swing with professional golfers. | Detail | Ranges | | --------- | ---------------------------------------------------------------------------------------------------------------------------------- | | Who | Professional golfers, between 10 and 15 in each group | | Groups | Men and women, each hitting a driver and an iron | | Positions | Address, the top and impact, plus tempo across the whole swing | | Metrics | Torso Turn, Pelvis Turn, X-Factor, Torso Forward Bend, Torso Side Bend, Torso Sway, Pelvis Sway, Torso Lift, Pelvis Lift and Tempo | | Green | Within 1 standard deviation of the professional average | | Orange | Within 2 standard deviations | | Red | More than 2 standard deviations away | The ranges reflect elite professionals, so they won't suit every golfer, swing speed or body type. Red doesn't mean wrong. To turn the colors on or off, see [Reference ranges](/sports/golf-analysis/using-3d-data-and-visualization.md#reference-ranges). ## Where your video is processed * **On your device.** The 3D is worked out on your iPhone or iPad. Your video isn't sent anywhere to be analyzed. * **Offline.** Once the AI models are downloaded, 3D works without an internet connection. See [Turn on 3D and download the AI models](https://github.com/Onform-Inc/onform-docs/tree/main/get-started/set-up/how-to-enable-3d-processing-and-download-the-latest-ai-models.md). * **Saved with your video.** The finished 3D is stored with the video in your Onform account, so it's ready on your other devices and for others in the workspace who have 3D. ## Related * [Analyze a swing in 3D](/sports/golf-analysis/using-3d-data-and-visualization.md) * [3D questions and problems](/sports/golf-analysis/3d-faqs.md) * [Read a kinematic sequence](/sports/golf-analysis/beginners-guide-to-kinematic-sequence.md) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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