asset-importer-sys

Low-level FFI bindings for the Assimp 3D asset import library.

This crate provides unsafe Rust FFI bindings for Assimp v6.0.2, implementing the vast majority of the C API functions, types, and constants.

Status

⚠️ Early Development: These bindings are functional but need more testing across different platforms and use cases.

Overview

This crate provides unsafe Rust bindings to the Assimp v6.0.2 C API, implementing the vast majority of functions, types, and constants. For a safe, high-level API, use the asset-importer crate instead.

API Coverage

The bindings include:

• Core Import/Export Functions: All major scene loading and saving functions
• Data Structures: Complete type definitions for scenes, meshes, materials, animations, etc.
• Post-Processing: All available post-processing steps and configurations
• Metadata Access: Scene and node metadata querying
• Memory Management: Proper resource cleanup and memory handling
• Logging System: Integration with Assimp's logging infrastructure

Build Features

Default: Uses prebuilt binaries for fastest builds.

Prebuilt Binaries (Default)

[dependencies]
asset-importer-sys = "0.3"
# or explicitly:
asset-importer-sys = { features = ["prebuilt"] }

• Downloads prebuilt libraries from GitHub releases
• No build dependencies required
• Fastest option for development

Build from Source

asset-importer-sys = { version = "0.3", features = ["build-assimp"] }

• Builds assimp from bundled source
• Requires: CMake, C++ compiler, Git
• Full control over build configuration
• Best compatibility across platforms

System Library

asset-importer-sys = { version = "0.3", features = ["system"] }

Uses system-installed assimp. Install via package manager:

• macOS: brew install assimp
• Ubuntu/Debian: sudo apt install libassimp-dev
• Windows: Use vcpkg or manual installation

On Windows with vcpkg, pick a triplet that matches your desired CRT:

• x64-windows → dynamic CRT (/MD)
• x64-windows-static → static CRT (/MT)

If you use the static triplet, also enable Rust crt-static so all crates agree:

# .cargo/config.toml
[target.x86_64-pc-windows-msvc]
rustflags = ["-C", "target-feature=+crt-static"]

Static Linking

asset-importer-sys = { version = "0.3", features = ["static-link", "build-assimp"] }

• Creates single executable with fewer external runtime dependencies
• Larger binary size

Additional Options

asset-importer-sys = {
    version = "0.3",
    features = [
        "build-assimp",
        "export",        # Enable export functionality
        "nozlib",        # Don't link zlib
        "mint",          # Math library interop
        "type-extensions" # Convenience methods
    ]
}

Environment Variables

• ASSIMP_DIR: Path to an Assimp source tree to use when the assimp submodule is not present (builds from this directory).
• ASSET_IMPORTER_PACKAGE_DIR: Use local prebuilt packages
  • On Windows we publish both -md and -mt suffixed archives; the build script selects the right one automatically and falls back to the old name if not found.
• CMAKE_GENERATOR: Override CMake generator (e.g., "Ninja")

Platform Support

Tested Platforms

• Windows (MSVC, MinGW)
• macOS (Intel, Apple Silicon)
• Linux (x86_64)

Build Requirements

Detailed Requirements for Source Build

Essential Tools:

• CMake 3.10+: Build system generator
• C++ Compiler:
  • Windows: MSVC 2019+ (Visual Studio Build Tools)
  • macOS: Clang (Xcode Command Line Tools)
  • Linux: GCC 7+ or Clang 6+
• Git: For submodule management

Platform Setup:

Windows:

# Install Visual Studio Build Tools or Visual Studio Community
# Or use chocolatey:
choco install cmake visualstudio2022buildtools

macOS:

# Install Xcode Command Line Tools
xcode-select --install

# Install CMake via Homebrew (recommended)
brew install cmake

Linux (Ubuntu/Debian):

sudo apt update
sudo apt install build-essential cmake git

Linux (CentOS/RHEL):

sudo yum groupinstall "Development Tools"
sudo yum install cmake3 git

Usage

use asset_importer_sys as sys;
use std::ffi::CString;
use std::ptr;

unsafe {
    let importer = sys::aiCreateImporter();
    let filename = CString::new("model.obj").unwrap();
    
    let scene = sys::aiImportFile(
        filename.as_ptr(),
        sys::aiProcess_Triangulate | sys::aiProcess_FlipUVs
    );
    
    if !scene.is_null() {
        let scene_ref = &*scene;
        println!("Loaded {} meshes", scene_ref.mNumMeshes);
        sys::aiReleaseImporter(importer);
    }
}

Goals

Provides comprehensive FFI bindings for the latest Assimp with flexible build options and optional convenience features.

Bindings Generation

Bindings are generated using bindgen from the Assimp headers. The generated bindings include:

• All ai* functions
• All ai* types and constants
• Proper struct layouts for FFI

Safety

This crate provides unsafe bindings. Memory management, null pointer checks, and proper API usage are the caller's responsibility. Consider using the safe asset-importer wrapper instead.

Contributing

Help needed with:

• Testing on more platforms
• Improving build reliability
• Documentation for advanced features

License

Licensed under either of:

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

at your option.