Edit a model

You can edit a model after you create or load it, using the Sentis Functional API.

Preprocess inputs or postprocess outputs

Sometimes your model expects inputs or returns outputs in a format that doesn't match your tensor data. Use the Functional API to prepend operations to inputs, append operations to outputs, or to easily add or remove inputs or outputs.

In the following example the mnist-8 model is adjusted to return the softmax of the output.

using UnityEngine;
using Unity.Sentis;

public class AddOutput : MonoBehaviour
{
    ModelAsset modelAsset;

    void Start()
    {
        // Load the source model from the model asset
        Model model = ModelLoader.Load(modelAsset);

        // Define the forward method of the model.
        // In this example an array of `FunctionalTensor` outputs is calculated from an array of `FunctionalTensor` inputs.
        FunctionalTensor[] ForwardWithSoftmax(FunctionalTensor[] inputs)
        {
            // Apply the model forward function to the inputs to get the source model functional outputs.
            // Sentis will destructively change the loaded source model. To avoid this at the expense of
            // higher memory usage and compile time, use the model.ForwardWithCopy method.
            FunctionalTensor[] outputs = model.Forward(inputs);

            // Calculate the softmax of the first output with the functional API.
            FunctionalTensor softmaxOutput = Functional.Softmax(outputs[0]);

            // Return an array containing the output.
            return new[] { softmaxOutput };
        }

        // Build the model from the using the `Compile` method. The input defs are taken from the original model.
        var modelWithSoftmax = Functional.Compile(ForwardWithSoftmax, InputDef.FromModel(model));
    }
}

Sentis runs model optimization on models you create using the Functional API. The Sentis operations used may, therefore, look different than expected.

Additional resources