AR face masks and filters: from prototype to production
Masks and filters are the most widespread face AR scenario. Snapchat, Instagram Reels, and TikTok have trained users to expect a certain quality. If a mask "swims" on head rotation or fails to react to facial expressions, the user deletes the app. We have faced this many times: over 5+ years and 30+ AR projects, we've developed an approach that guarantees stability and realism. Technically, the task is well solved with ARKit and RealityKit, but there are nuances with occlusion, animation, and video recording. Below is how we tackle these challenges.
Types of masks and their technical implementation
Geometric mask — a 3D mesh stretched over the face that follows its deformations. The most realistic option. In RealityKit we use a ModelEntity with a skinned mesh whose joints are tied to ARKit blendShapes:
// Face Anchor as root
let faceAnchor = AnchorEntity(.face)
// Load USDZ with morph targets matching ARKit blendShapes
let maskEntity = try! ModelEntity.load(named: "zombie_face.usdz")
faceAnchor.addChild(maskEntity)
arView.scene.addAnchor(faceAnchor)
// In update loop — apply blendShapes to mask morph targets
func session(_ session: ARSession, didUpdate anchors: [ARAnchor]) {
guard let faceAnchor = anchors.first as? ARFaceAnchor else { return }
// BlendShape mapping: ARKit jawOpen → mask jaw morph target
}
Flat sticker/overlay — a 2D image or video attached to a face anchor. Simpler to implement, fewer deformations. Suitable for frames, "hats", fake mustaches. Particle effects — particles attached to face points (sparks from eyes, smoke from mouth when jawOpen > 0.3). In RealityKit — an Entity with a custom particle system via Reality Composer Pro.
| Mask type | Realism | Complexity | Use cases |
|---|---|---|---|
| Geometric | High | High | Zombies, animals, complex characters |
| Flat sticker | Low | Low | Frames, mustaches, hats |
| Particle effects | Medium | Medium | Sparks, smoke, glitter |
How to achieve realistic occlusion?
The main technical subtlety: virtual mask elements (horns, crown, glasses) must be blocked by the real face where physically correct. A crown goes behind the head — the back of the head occludes it. Glasses "sit" on the nose — the nose overlaps the temples.
In ARKit/RealityKit — an occluder mesh: a copy of the face geometry with an .occlusion material. This mesh is invisible to the user but writes depth to the depth buffer. Elements "behind" the face are correctly occluded:
// Occluder entity — invisible face copy
var occluderMaterial = OcclusionMaterial()
let occluderEntity = ModelEntity(
mesh: .init(arFaceGeometry: faceAnchor.geometry),
materials: [occluderMaterial]
)
faceAnchor.addChild(occluderEntity)
Without an occluder, horns poke through the head from any angle — looking cheap. Our experience shows this step is missed by 70% of novice developers.
Animation by facial expressions: why is it complex?
52 ARKit blendShapes — mapping to morph targets of the 3D mask. Standard scenario: a zombie mask opens its mouth on jawOpen, squints eyes on eyeBlinkLeft/Right. The mask mesh must have corresponding morph targets with the same names or via a mapping table.
Reality Composer Pro allows configuring BlendShapeWeightsMapping directly in USDZ without code. For complex animations — a custom update in ARSessionDelegate:
// Pass blendShapes to mask shader parameter
maskEntity.model?.materials[0].setParameter(
name: "jawOpen",
value: .float(faceAnchor.blendShapes[.jawOpen]?.floatValue ?? 0)
)
Correct mapping improves mask responsiveness by 2–3 times compared to the default. We verify animations on several face types to avoid distortions.
Video recording with an AR mask
RPScreenRecorder (ReplayKit) — records the entire screen including the AR view. Simple but low quality (records what's on screen, including UI elements). For clean AR camera recording — ARView.session + custom CVPixelBuffer rendering via Metal:
// Composite: camera frame + AR overlay → CVPixelBuffer
// → AVAssetWriter → .mp4
This is more complex but provides a clean recording without UI overlay and with custom resolution options. We use this approach in projects requiring high-quality video export.
Lens Studio / Spark AR as an alternative
If the goal is a viral filter for Snap/Instagram/TikTok, not your own app: Lens Studio (Snap) and Meta Spark (Instagram) provide visual development environments without native coding. Effects are published on the platform and available to users in the native apps.
For a custom mobile app with its own camera — only native implementation or a Banuba Face AR SDK. Our engineers work with both approaches and can assess which suits you.
What our work includes
- Analysis and prototyping of the mask (type selection, design, animations)
- 3D mesh modeling or 2D sticker preparation
- Occluder and blendShape mapping setup
- Integration with your app (Swift/SwiftUI, Kotlin, Flutter)
- Testing on 5+ devices and bug fixing
- Assistance with App Store / Google Play publication (if needed)
- Integration documentation and 2‑week post‑delivery support
Timelines and cost
A basic static mask (static 3D mesh, no blendShape animation) — 4–6 days. An animated mask with face occluder and 3–5 blendShape reactions — 2–3 weeks. Video recording plus a mask gallery with cloud upload — additional 2–3 weeks. Cost is determined individually after evaluating your task. Get a consultation — contact us, and we'll send a preliminary commercial proposal within a day.







