Serialize a Model

For larger models, it's advisable to use a serialized asset, which typically comes with the file extension .sentis.

Create a serialized asset

After you import your ONNX model into the Unity project, follow these steps:

  1. Select the model file in the Project window.
  2. In the Inspector window, select Serialize to StreamingAssets.

Unity creates a serialized version of the model and saves it as a .sentis file in the StreamingAssets folder.

Load a serialized asset

To load a serialized model in your project at runtime, use the following code:

Model model = ModelLoader.Load(Application.streamingAssetsPath + "/mymodel.sentis");

Replace mymodel.sentis with the name of your serialized model file.

Advantages of using serialized models

Some advantages of using a serialized model are as follows:

  • Saves disk space in your project
  • Faster loading times
  • Validated to work in Unity
  • Easier to share

Serialization layout

Inference Engine serializes a .sentis file with FlatBuffers.

             ┌───────────────────────────────────┐
             │Flatbuffer-serialized              |
             | model desription                  │
             │                                   │
          ┌─ ├───────────────────────────────────┤
          │  │ Weight chunk data                 |
          │  │                                   │
          │  │                                   │
Weights  ─┤  ├───────────────────────────────────┤
          │  │ Weight chunk data                 │
          │  │                                   │
          │  │                                   │
          │  ├───────────────────────────────────┤
          │  │...                                │
          └─ └───────────────────────────────────┘

For more information, refer to Inference Engine/Runtime/Core/Serialization/program.fbs.

Additional resources