Lens studio assets and fbx

Assets, materials & 3D models in Lens Studio

Getting textures, materials, and 3D meshes into a project and wired up.

Importing a texture: just drop the file in Assets/

Copy a PNG into the project's Assets/ folder on disk — Lens Studio's file watcher auto-imports it as a FileTexture, and overwriting it hot-reloads. Verify with ListLensStudioAssets assetTypeFilter:FileTexture nameFilter:"...". Generate gradients / icons / rounded buttons with PowerShell System.Drawing and drop them straight in.

This same "write into Assets/" path is how you create a new TypeScript file too (it compiles on import). The MCP ReadWriteTextFile writes project files with a path relative to Assets (e.g. PiPi/Scripts/Foo.ts); the plain Write tool to the absolute on-disk path also works and the watcher picks it up.

Materials and their texture slots (what IS and ISN'T MCP-settable)

• Image material (ImageMaterialPreset): has baseTex and alpha-blends. Set the visual's mainMaterial (reference) then mainMaterial.passInfos.0.baseTex (reference). Tint via the Image component baseColor. The plain Unlit preset has no texture slot — don't use it for images.
• PBR / Image material texture slots ARE settable: mainMaterial.passInfos.0.baseTex and ...normalTex take texture-UUID references over MCP. Good for swapping real PBR maps (e.g. Poly Haven wood/grass) onto a mesh.
• A PBR material's scalar baseColor is NOT reliably settable via MCP (the Image material's baseColor is). Plan tints accordingly.
• Colors on materials still follow the component-by-component rule (mcp-editing): ...baseColor.x/.y/.z as number.

Fluffy / fur / cloth look: UberPBR + a CC0 fur texture (not the hair presets)

To make an ordinary mesh read as fluffy/furry, the reliable route is PBR + a real fur texture, not the built-in hair shaders:

1. Create an UberPBRMaterialPreset material; assign it to the mesh's visual.
2. Set mainMaterial.passInfos.0.baseTex and ...normalTex to a tiling CC0 fur texture — Poly Haven (polyhaven.com) is the easy source; e.g. curly_teddy_natural gives a diff (→ baseTex) and a nor_gl (→ normalTex) map, downloadable from https://dl.polyhaven.org/.... The normal map does most of the "fuzz".
3. High roughness, metallic = 0, and tint via baseColor (component-by-component — mcp-editing).

Avoid the built-in hair presets (HairGlowingOrange, HairCurlyBlue, …) for this: they expect groom/strand geometry with hair UVs and look wrong stretched across an arbitrary solid mesh. They're for actual hair cards, not "make this blob fluffy." Prefer the PBR-fur approach on ordinary meshes.

Asset housekeeping gotchas

• DuplicateLensStudioAsset → key is assetUUID (not assetId).
• MoveLensStudioAsset → key is destinationPath (not destinationFolderPath).
• Some presets people expect don't exist (BoxMeshPreset, NunitoFontPreset, BalsamiqSansFontPreset). Check GetPresetRegistryTool before assuming a preset name; substitute (e.g. a cylinder mesh, PacificoFontPreset/IndieFlowerFontPreset).
• Organize by creating folders and MoveLensStudioAsset-ing into them; keep generated textures and models in their own subfolders so re-imports don't collide.

3D models (FBX / GLB)

Drop the .fbx/.glb into Assets/ → LS imports it as mesh(es) + material(s) + an ObjectPrefab. Instantiate with InstantiateLensStudioPrefab <prefabUUID> parentUUID:<...>. Then set its transform component-by-component. Notes:

• Imported model scale is unpredictable; expect to rescale hard after instantiating. (AI-generated meshes via GenerateFast3DAssets come in ~1 cm longest-axis but get a default ×100 prefab scale — i.e. ~100 cm — so always adjust.)
• A 3D model used as a "logo" reads as genuinely 3D and can idle-spin via a tiny UpdateEvent rotation — a nicer "3D version" of a flat PNG logo.
• FBX may reference external textures; keep them alongside the FBX in the same folder so the import resolves them.

Pulling PRIVATE files off Google Drive into the project

You'll often be handed a Drive folder of assets (models, logos). Two hard truths:

1. Routing bytes through the agent's context doesn't scale. The Drive MCP download_file_content returns base64 into your context — even a 200 KB file is ~50k tokens; an 800 KB FBX is unusable. Use it only to enumerate (search_files parentId='<folderId>', get_file_metadata), never to fetch binaries.
2. Unauthenticated direct download fails for private files. https://drive.google.com/uc?export=download&id=<ID> returns a Google sign-in HTML page, not the file, unless you carry the owner/viewer's session.

The working pattern — download to disk with the user's browser cookies, bytes never touching context:

# inside a browser tool connected to the user's logged-in Chrome:
res = cdp("Network.getAllCookies", {})           # CDP returns httpOnly cookies too (the SID ones)
cookies = {c["name"]: c["value"] for c in res["cookies"] if c["domain"].endswith("google.com")}
s = requests.Session(); s.cookies.update(cookies)
r = s.get("https://drive.google.com/uc?export=download&id="+fid, allow_redirects=True)
if "text/html" in r.headers.get("content-type",""):   # virus-scan / confirm interstitial
    import re, html
    m = re.search(r'action="([^"]+)"', r.text)         # resubmit the confirm form
    act = html.unescape(m.group(1)); params = dict(re.findall(r'name="([^"]+)" value="([^"]*)"', r.text))
    r = s.get(act, params=params, allow_redirects=True)
open(dest, "wb").write(r.content)

Prereqs & checks:

• The browser must be reachable over CDP and logged into the account that can see the folder. Verify: hit http://127.0.0.1:<port>/json/version; confirm Chrome is up with remote debugging on. Plain Chrome running ≠ debugging enabled — it's a per-profile opt-in (chrome://inspect) or a --remote-debugging-port launch with a non-default --user-data-dir. An isolated debug profile won't have the user's Google login, so it can't see private files — you need the real profile.
• After download, sanity-check magic bytes (FBX binary starts with Kaydara FBX Binary; PNG with \x89PNG). An HTML blob where a model should be = you got the sign-in page; auth isn't wired.
• If you can't get an authenticated browser, stop and ask the user to enable remote debugging / start their automation browser, or to drop the files in Assets/ themselves. Don't burn cycles on unauthenticated downloads.

Related: ui-building (using textures as image planes), custom-shaders (PBR/graph materials).