Bunny Viewer

Bunny Viewer is a user-friendly STL/PLY file viewer, written in Rust as a side-project with a huge help from ChatGPT + Codex. It targets developers who want a fast, native mesh viewer on macOS and iPadOS.

Features

• Loads .ply and .stl triangular meshes.
• GPU rendering with optional bicubic upsampling.
• macOS app + iPad app (Xcode project).
• CLI utilities for decoding and inspection.

Install (macOS)

From the repo root:

cargo install --path app

This installs:

• mesh-viewer (GUI viewer)
• mesh-decode (CLI mesh decoder)

Run

mesh-viewer --file ./path/to/mesh.ply

If no file is passed, the app loads a bundled sample mesh from: ~/Library/Application Support/Mesh Viewer/meshes/sample.ply

CLI flags

--file <path>          Mesh file path (.ply/.stl)
--camera <preset>      front|side|top|iso (aliases: right,isometric)
--render-scale <f32>   Render scale (1.0-2.0)
--log-level <filter>   tracing log filter

Controls

macOS

• Left-drag: orbit
• Right-drag: pan
• Scroll: dolly (zoom)
• WASD: move target
• Arrow keys: orbit (yaw/pitch)
• Checkbox: "No culling" toggles backface culling

iPadOS

• One-finger drag: orbit
• Two-finger drag: pan
• Pinch: dolly (zoom)

iPad build

Open ios/MeshViewer/MeshViewer.xcodeproj in Xcode and build the MeshViewer target.

Render scale behavior

• macOS: uses the --render-scale CLI flag (or MESH_RENDER_SCALE env var if set).
• iPadOS: respects MESH_RENDER_SCALE when culling is enabled, and forces scale to 1.0 when "No culling" is enabled to avoid bicubic upsampling.

Development

cargo test --all

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT License (LICENSE-MIT)