Avalonia Veldrid 3D STL Viewer

I successfully integrated a 3D STL model renderer into an Avalonia application. The process took approximately a week and a half, including overcoming an initial issue with the Raspberry Pi setup. After resolving the Raspberry Pi configuration, the main challenge was displaying the 3D view within the Avalonia window. This project is still under development, and I have plans for further enhancements, likely driven by a larger product this component is being built for. Please review the setup instructions carefully before attempting to run the sample.

TODO:

• Camera movement
• Model rotation
• Support for multiple models per view or importing models
• Incorporate bone structure

Setup Instructions:

When running this sample, you will likely encounter the following error related to Veldrid's SPIR-V support:

This error is common with Veldrid, even outside of this specific project. To resolve it, you must build veldrid-spirv from its source code.

1. Clone the veldrid-spirv repository: Make sure to use the --recurse-submodules flag to fetch all necessary dependencies:

   git clone --recurse-submodules [https://github.com/veldrid/veldrid-spirv.git](https://github.com/veldrid/veldrid-spirv.git)

2. Navigate to the cloned directory:

   cd veldrid-spirv

3. Synchronize shaderc: Run the provided script to obtain the required shaderc files:

   ./ext/sync-shaderc.sh

4. Build the native library: Build the library for your platform (Linux arm64 in this case). You do not need to modify the build script, despite what might be mentioned in other instructions.

   ./build-native.sh -release linux-arm64

5. Copy the library file: Copy the resulting .so file to the appropriate .NET shared framework directory. Replace 9.0.0 with the exact .NET version your project is using. You can find this version by looking at your project's .csproj file (look for <TargetFramework>net9.0</TargetFramework> or similar, use the version number there, eg: 6.0.25, 7.0.14, 8.0.2). Use the correct path for the shared folder of the correct dotnet version!

   sudo cp veldrid-spirv/build/Release/linux-x64/libveldrid-spirv.so /opt/dotnet/shared/Microsoft.NETCore.App/9.0.0/

   • Important: If the /opt/dotnet/shared/Microsoft.NETCore.App/9.0.0/ directory doesn't exist, you either have the wrong .NET version, or .NET isn't installed in the standard location. You might have .NET installed through a package manager in a different place (e.g., /usr/share/dotnet/shared/Microsoft.NETCore.App/). Use dotnet --info to get information about your .NET installation, which can help you locate the correct shared framework directory.
   • If the file already exist.

   sudo mv /opt/dotnet/shared/Microsoft.NETCore.App/9.0.0/libveldrid-spirv.so /opt/dotnet/shared/Microsoft.NETCore.App/9.0.0/libveldrid-spirv.so.bak
   sudo cp veldrid-spirv/build/Release/linux-x64/libveldrid-spirv.so /opt/dotnet/shared/Microsoft.NETCore.App/9.0.0/

   • Note for Raspberry Pi: If you are building directly on a Raspberry Pi, the architecture might be arm64 or armhf instead of linux-x64. Adjust the build-native.sh command accordingly (e.g., ./build-native.sh -release linux-arm64).

After completing these steps, the sample project should run without the SPIR-V error.

(Thanks to this osu forum post for the solution: https://osu.ppy.sh/community/forums/topics/1870817?n=1)

Working View