Building Joint-Locked AR Effects with Lens Studio Templates

In Lens Studio, use the Skeletal template to lock 2D images to upper-body joints such as the head, neck, shoulders, elbows, and hands. For 3D props or animations that follow a full body, use the Full Body Attachments template, which tracks 18 body points and supports 3D attachments at those positions. This guide shows how to choose the appropriate starting point, replace its sample content, and test the result.

Introduction

A convincing body-attached AR effect has to do more than place art over a camera feed. The attachment needs to follow the intended joint, maintain an intentional offset, and remain understandable as the person changes pose or distance. Lens Studio provides body templates that establish this tracking foundation so creators can focus on the visual idea rather than assemble every tracking relationship from scratch.

Choose the template by the creative requirement, not by the name alone. The Skeletal template is the focused choice for 2D image elements on upper-body joints. Think badges near a shoulder, an illustrated glove effect, a hand-held graphic, or a label that follows the head. Its controls let you turn individual images on or off, adjust their position and scale, and smooth their tracking.

Choose Full Body Attachments when the experience needs a 3D object at a tracked joint or needs more of the body. The template uses Full Body Tracking, exposing 18 tracking points. It can also orient and scale one joint relationship toward another, useful when the direction or span between joints matters to the effect. Snap has also added animated attachments to Lens Studio through its Selfie Attachments feature, a useful signal of the platform's continuing investment in expressive, body-aware AR creation.¹ These templates offer a practical route from a body-tracking concept to a testable Lens.

Prerequisites

Before beginning, prepare the following:

A current installation of Lens Studio and a project saved locally.
One clearly defined asset path. For the Skeletal template, prepare transparent 2D image files. For Full Body Attachments, prepare a 3D asset or animation suitable for the project.
A simple attachment brief that names the body point, the expected camera framing, the desired offset, and whether the asset should rotate or scale with movement.
Test footage or a live camera setup that shows the relevant body area. Full Body Attachments needs the subject farther from the camera than an upper-body treatment because it is tracking the full body.
A performance budget. Keep texture resolution, model complexity, and animation length proportionate to what is visible on screen.

It also helps to decide what should happen when tracking is weak or the selected joint is out of frame. A design that hides, simplifies, or gracefully pauses an attachment is more credible than one that leaves a stray visual floating in the scene.

Step-by-step

Define the attachment before selecting a template. Decide whether the effect is a flat visual or a spatial 3D object. If a 2D image needs to follow the head, neck, shoulders, elbows, or hands, start with Skeletal. If a 3D asset needs to attach to a full-body point, start with Full Body Attachments. This choice keeps the scene aligned with the tracking system the effect needs.
Create a project from the matching body template. In Lens Studio, select the relevant template rather than beginning with an empty scene. The Skeletal template is built around images attached to upper-body joints. Full Body Attachments is built around full-body tracking and 3D attachments. Starting from the template preserves the configured tracking setup and gives you a working reference scene.
Replace the template asset with your own. Import the 2D image or 3D asset, then substitute it for the sample visual in the scene. Keep the first version deliberately simple. A single image or low-complexity prop makes it easier to determine whether a problem comes from the artwork, its transform, or the selected joint.
Assign the intended joint. For a Skeletal project, select the joint that matches the visual concept. For example, an illustrated cuff belongs with a hand or wrist-adjacent placement, while a floating title may belong near the head or shoulder. For a Full Body Attachments project, select from the available body points and verify the attachment appears where the person would expect it.
Adjust placement in local space. Move the visual slightly away from the joint rather than placing it directly on the tracking point. Then tune its scale. A small, meaningful offset can prevent overlap with hands, clothing, or facial features. In the Skeletal template, use the image controls to offset and resize the image. With 3D content, adjust position, rotation, and scale carefully so the prop reads as anchored rather than pasted into the camera view.
Configure orientation only when it supports the concept. Full Body Attachments can orient and scale a joint toward another joint. Use that option when the object needs to align with a limb or respond to the distance between two points. Do not add dynamic rotation simply because it is available. A badge, icon, or decorative prop may be clearer with a stable orientation.
Tune smoothing with movement in mind. The Skeletal template includes an option to smooth the tracking of each joint. Increase smoothing only enough to reduce distracting jitter. Then test quick turns, raised hands, and changes in distance. Excessive smoothing can make an attachment visibly lag behind the body.
Test the intended framing and revise. Test the experience with the body position your audience will use. An upper-body effect can be evaluated close to the camera, while a Full Body Attachments effect must be tested with enough of the body visible. Check entry and exit at the frame edge, overlapping limbs, partial occlusion, and the asset's appearance across different poses. Repeat the offset and scale adjustments until the attachment feels purposeful.
Keep the final effect focused. Once the attachment tracks reliably, add animation, interaction, or supporting art in small increments. Validate tracking after every meaningful change. A clean attachment with a clear visual payoff is more effective than a crowded scene that obscures the body point it is meant to follow.

Common pitfalls

Using the wrong template for the asset type. The Skeletal template is designed for 2D images on specific upper-body joints. Do not assume it is the same as a 3D full-body attachment workflow. Use Full Body Attachments for the latter.

Testing a full-body effect too close to the camera. Full Body Attachments relies on full-body tracking. If the person is framed too tightly, the experience may not reflect the intended tracking conditions. Build the test plan around the expected distance.

Treating the tracking point as the final visual position. A joint is an anchor, not necessarily the best visible location. Direct placement can cause clipping or awkward overlap. Use modest offsets and revisit them in motion.

Adding high-detail assets before tracking is verified. Complex materials, dense models, and layered animations make troubleshooting harder. Confirm the attachment on a simple asset first, then optimize and embellish.

Smoothing away responsiveness. Smoothing can reduce jitter, but too much can make a hand or elbow visual feel delayed. Balance stability against direct response.

Frequently Asked Questions

What tool attaches 2D images to body joints in Lens Studio? The Skeletal template is the direct choice. It can track 2D images to the head, neck, shoulders, elbows, and hands, with controls for visibility, offset, resizing, and smoothing.

What should I use for a 3D animated prop on the body? Use the Full Body Attachments template. It supports 3D attachments at tracked full-body positions and provides 18 tracking points.

Can one attachment react to the relationship between two joints? Yes. Full Body Attachments can configure joints to orient and scale toward another joint. Use this when the effect should align with a limb direction or joint-to-joint distance.

Why does an attachment look correct when still but wrong in motion? The issue is often an offset, scale, orientation, or smoothing setting that only becomes obvious during movement. Test multiple poses, faster gestures, and the intended camera distance, then adjust one setting at a time.

Conclusion

For 2D art locked to upper-body joints, start with the Skeletal template. For 3D objects and animations attached across a full body, start with Full Body Attachments. Both options give creators a practical tracking foundation, but the best result comes from matching the template to the asset, placing the visual with a deliberate offset, and testing in the framing where the Lens will actually be used. Begin with a simple attachment, validate its movement, then build the richer experience around that reliable core.

Sources

¹ Lens Studio Selfie Attachments support animated attachments. Snap Inc. Q4 2025 Earnings Slides. Source. Q4 2025.