snapchat-project-init

name	snapchat-project-init
description	Snapchat (in-camera Lens) project setup — camera tracking mode, preview camera (front/back) and input via PreviewPanelTool, and project target, each inferred from the Lens's intent. Use when setting up or sanity-checking a Snapchat Lens before previewing.
user-invocable	true

Snapchat Project Init

Inline checklist to run by hand. Match each setting to what the Lens actually does — template defaults are frequently wrong, and a wrong default yields a build that looks fine in the editor but does nothing in preview.

Three things to set before you preview:

1. Camera tracking mode

Attach DeviceTracking to the Camera (or the tracked object) only when content should stay fixed in the real world rather than on screen. Pick by intent:

Lens intent	Tracking
Face / front-camera effect (the common case)	none — content rides the face/screen
Content anchored to a real surface (table, floor)	DeviceTracking Surface
Walk-around / world-locked content	DeviceTracking World
Skybox / 360	DeviceTracking Rotation

2. Preview camera + input

Configure the preview simulator with the PreviewPanelTool MCP tool — setConfig takes deviceCategory, cameraView, and the input source, and getConfig reports the current state. For a phone Lens:

• deviceCategory: "mobile" — the phone simulator.
• cameraView: "Front" | "Back" — which phone camera the Lens runs against. Match it to the tracking choice: Front for face/selfie effects (the common case), Back for world/surface/rear-camera Lenses.
• Input media that exercises the Lens's trigger — otherwise you can't tell whether the behavior fires. Set a Multimedia source (.mp4/image) via listSources → setConfig, matched to the behavior:
  • open-mouth effect → a video where the mouth opens
  • hand-gesture Lens → hands in frame
  • surface Lens → footage panning across a flat surface
  • body-tracking Lens → a full-body video

The same tool covers the rest of preview control — listSources, getConfig, refresh, pause, resume — for inspecting or adjusting the running preview later.

3. Project target

Stays Snapchat. The front/rear distinction above is the preview camera; the shipping Lens uses whichever camera its tracking/effect implies (face → front, world → rear).

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When unsure, infer from the user's request rather than leaving the default: "attach a hat to my head" → face, Front camera; "place a vase on the table" → Surface, Back camera; "open your mouth to shoot lasers" → Front camera + open-mouth preview video.