Model Viewer (asset-importer + wgpu)

This is a small model viewer built on top of the Assimp Rust binding asset-importer. It serves as a practical sample and a testbed to validate asset-importer across common formats.

Highlights

• WGPU + Winit + EGUI (wgpu v25, winit v0.30, egui v0.32)
• Assimp-driven loading via asset-importer v0.4 (external and embedded textures)
• Physically-Based Rendering (metallic-roughness)
  • Base color, normal, metallic-roughness, occlusion, emissive
  • UV0/UV1, per-texture UV transforms, vertex colors
• Image-Based Lighting (IBL)
  • Generates irradiance, prefiltered environment (mips), and BRDF LUT from HDR
  • Cubemap skybox rendered from the environment
• Lights: multiple punctual lights imported from the scene
• Multi-pass forward renderer
  • Skybox → Opaque → Two-Sided → OpaqueTransparent → Transparent
  • Basic transparent sorting; alpha-mask and blend paths
• Debug views and GUI panel (output channels, material info, basic controls)

Build & Run

cargo run --bin download-assets
cargo run --bin model-viewer -- "assets/glTF-Sample-Assets-main/Models/DamagedHelmet/glTF/DamagedHelmet.gltf"

Point it at any supported model file; the glTF-Sample-Assets Helmet is a good sanity check.

Notes:

• The downloader fetches both the glTF Sample Assets and a default IBL HDRI (venice_sunset_1k.exr) into assets/ibl/ for PBR/IBL rendering.
• You can replace the EXR with your own HDR/EXR in assets/ibl/.

CLI Options

Run model-viewer -h for the full list. Common flags:

• --width <u32> / --height <u32>: Window size (default 800x600)
• --background <#RRGGBB>: Clear color (default #202020)
• --verbose: Enable debug logging

Rendering:

• --exposure <f32>: Exposure for ACES tone mapping (default 1.0)

Animation:

• --no-anim: Disable animation playback
• --anim-index <usize>: Select which animation to play (0-based, default 0)
• --anim-speed <f32>: Playback speed multiplier (default 1.0)

Examples:

# Play animation 1 at 2x speed
cargo run --bin model-viewer -- "assets/glTF-Sample-Assets-main/Models/Fox/glTF/Fox.gltf" \
  --anim-index 1 --anim-speed 2.0 --exposure 1.25

# Disable animation
cargo run --bin model-viewer -- "assets/glTF-Sample-Assets-main/Models/CesiumMan/glTF/CesiumMan.gltf" --no-anim

Notes

• This project is focused on feature coverage and correctness as a companion to asset-importer, not raw performance.
• Tested primarily on desktop (wgpu Vulkan/DirectX backends).