Android Assimp 3D Playground — Models

Public sample pack of Earth, Moon, SciFi orb, ClockSample, and a BusterDrone reference entry (docs + shots only — glTF not redistributed) for Assimp-based viewers and Android / Vulkan playgrounds.

Each local mesh model ships as Wavefront OBJ + MTL and Discreet 3DS, with maps / textures where applicable, plus a short INFO.txt. BusterDrone is link-only (CC BY-NC upstream).

Layout

models/
  earth/          Earth globe — albedo, bump, normal, specular + shots/
  moon/           Moon globe — NASA SVS CGI Moon Kit maps + shots/
  scifi-orb/      Multi-material sci-fi orb (materials only) + shots/
  clock-sample/   POV clock scene + moon prop + shots/
  buster-drone/   INFO + shots only — glTF from Filament / Sketchfab (CC BY-NC)
tools/
  obj_to_3ds.py   Small OBJ→3DS helper used for Earth / Moon

Model	OBJ / MTL	3DS	Maps	Shots
Earth	yes	yes	albedo, bump, normal, specular	01 … 10 (folder)
Moon	yes	yes	albedo, bump, normal, specular	01 … 10 (folder)
SciFi orb	yes	yes	none (Ka/Kd/Ks/Ke)	01 … 10 (folder)
ClockSample	yes	yes	checker, stripe, Moon_*	01 … 10 (folder)
BusterDrone	no (link)	no	PBR MR upstream	01 … 10 (folder)

Orbit stills (representative)

Earth	Moon	SciFi orb	ClockSample	BusterDrone

Each model has 10 emulator screenshots (shots/01.png–10.png) from the Vulkan SceneViewer (orbit auto-spin). How they were captured — and that this pack grew out of an AI-assisted Android/Assimp lighting workflow — is under How the shots were made. (Emulator MP4s were dropped: headless screenrecord was too janky to keep.)

Quick start

1. Clone or download this repository.
2. Point your Assimp (or other) loader at e.g. models/earth/Earth.obj or models/earth/Earth.3DS.
3. Keep texture files next to the mesh (paths in MTL / 3DS are basenames).
4. Read models/<name>/INFO.txt for map meanings and usage tips.
5. BusterDrone: fetch scene.gltf from Filament (see models/buster-drone/INFO.txt) — not included here.

Recommended load flags (Assimp-style)

• OBJ: enable diffuse + specular + specular-map + bump/height + normals.
• 3DS: same, but expect generated mesh normals (no NORMALS chunk); bump / height and specular maps are present for Earth, Moon, and ClockSample’s moon.
• glTF (BusterDrone): glTF importer + Draco (or decode first); aiProcess_PreTransformVertices; metallic-roughness shading (not Blinn-only).

How the shots were made

These stills are not offline renders. They come from the same Vulkan SceneViewer used while iterating Earth/Moon specular, sunglint, and normal maps in an AI-assisted coding session (Cursor agent + human review on a headless Android/NDK host). The goal was a quick, honest look at how the meshes light in a real Assimp → Vulkan path — the kind of check that showed up repeatedly while doing that AI-related lighting/asset work.

Short-lived emulator MP4s (adb screenrecord + orbit swipes) were recorded the same way, but they stuttered badly on the headless AVD, so only PNG frames remain in the repo.

Pipeline (short)

1. Start AVD medium_phone headless (emulator -avd medium_phone -no-audio -no-window).
2. Install the debug APK of PingPong2026Assimp (debuggable so prefs can be written via run-as).
3. Launch .SceneViewerActivity once so assets/bundled_models/ extract under the app’s files/bundled_models/.
4. For each model, force-stop the app, write SharedPreferences (mesh_id=6 + custom_obj_path → Earth.obj / Moon.obj / SciFiOrb.obj / ClockSample.obj / BusterDrone/scene.gltf, material/map toggles on, camera_engine=orbit), then start the viewer again.
5. Wait for orbit auto-spin, then capture 10 frames over ~25 s via adb exec-out screencap -p / android screen capture (AVD ~1080×2400).
6. Store as models/<name>/shots/01.png … 10.png.

Helper scripts for start/install/stop on this host live under the parent workspace skill emulator-adb-workflow (not required to use the model files themselves).

Licensing

• Original content (meshes, authored maps, docs, packaging, screenshot PNGs as documentation): CC0 1.0 — public domain dedication.
• NASA imagery (Moon kit, Earth Blue Marble lineage): public domain; please credit NASA / GSFC / SVS when practical.
• three.js Earth normal map and specular base: MIT — see ATTRIBUTION.md.
• BusterDrone mesh/textures: CC BY-NC (not in this repo) — see models/buster-drone/INFO.txt and ATTRIBUTION.md.

Model notes (short)

Earth — Unit sphere with ocean sunglint / polar ice specular authored on top of a MIT ocean mask; land stays near-matte. See models/earth/INFO.txt.

Moon — LROC albedo + LOLA-derived bump/normal (radius-matched strength) and a soft PD-authored regolith specular. See models/moon/INFO.txt.

SciFi orb — Dense hard-surface orb; metals + emissive accents, no textures.

ClockSample — Checker ground, striped clock, moon using the same Moon maps (copies included under models/clock-sample/).

BusterDrone — Filament / Sketchfab glTF (PBR, optional Draco). Docs + orbit stills only here; download the assets from Google’s Filament tree. Animation not shown in stills. See models/buster-drone/INFO.txt.

Regenerating Earth / Moon .3DS

python3 tools/obj_to_3ds.py models/earth/Earth.obj -o models/earth/Earth.3DS
python3 tools/obj_to_3ds.py models/moon/Moon.obj   -o models/moon/Moon.3DS

(SciFi orb and ClockSample .3DS files are pre-built; SciFi exceeds a single 3DS mesh face limit and was exported with mesh splitting.)