Edit a model

Use the Sentis Functional API to edit a model after you create or load it.

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 functional graph of the model.
        var graph = new FunctionalGraph();

        // Set the inputs of the graph from the original model inputs and return an array of functional tensors
        var inputs = graph.AddInputs(model);

        // 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 Functional.ForwardWithCopy method.
        FunctionalTensor[] outputs = Functional.Forward(model, inputs);

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

        // Build the model from the graph using the `Compile` method with the desired outputs.
        var modelWithSoftmax = graph.Compile(softmaxOutput);
    }
}

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

Note that Compile is a slow operation that uses a lot of memory. It is recommended to run this offline and to serialize the computed model. See Serialize A Model for details.

Additional resources