Use case: Querying metadata from raycasting

To accomplish this use case, do the following:

1. Upload an asset
2. Create a cloud streaming behavior
3. Set up a new scene

Before you start

Before you start, install the following Unity Cloud package dependency from the registry by name:

• unity.cloud.identity

For more information on how to install packages by name, see Installing a package by name

How do I...?

Upload an asset

To upload an asset, follow these steps

Create a cloud streaming behavior

To create a cloud streaming behavior and set up a new scene, follow these steps

Set up the MetadataRepository

To set up the MetadataRepository, refer to Set up a IMetadataRepository.

Use Data-Streaming to get an instance's metadata

Use the Data-Streamer's Raycaster

public async Task RaycastWithTheDataStreamer(IStage stage, Camera camera)
{
    await stage.RaycastAsync((DoubleRay)camera.ScreenPointToRay(Input.mousePosition), camera.farClipPlane);
}

By passing a Ray to the RaycastAsync method, you get a RaycastResult. A normal use-case would be to pass the mouse position converted into a ray.

Use the RaycastResult

public async Task UsingTheRaycastResult(IStage stage, Camera camera)
{
    var raycastResult = await stage.RaycastAsync((DoubleRay)camera.ScreenPointToRay(Input.mousePosition), camera.farClipPlane);

    if (string.IsNullOrEmpty(raycastResult.InstanceId.ToString()))
    {
        //no instance or no indexed texture was hit
    }
}

The RaycastResult contains a property named InstanceId. The string is empty if there is no hit with the raycast. This can be caused by:

• The raycast hit nothing
• The dataset is too old and doesn't contain an indexed texture.

Use the InstanceId for a metadata query

public async Task<MetadataInstance> QueryingTheInstanceMetadata(IStage stage, Camera camera, IMetadataRepository metadataRepository)
{
    var raycastResult = await stage.RaycastAsync((DoubleRay)camera.ScreenPointToRay(Input.mousePosition), camera.farClipPlane);

    MetadataInstance result = default;

    if (!string.IsNullOrEmpty(raycastResult.InstanceId.ToString()))
    {
        result = await metadataRepository
            .Query()
            .WhereInstanceEquals(raycastResult.InstanceId)
            .GetFirstOrDefaultAsync(default);
    }

    return result;
}

The obtained InstanceId can then be used directly into the metadata query builder's WhereInstanceEquals method. For more info on how to build metadata queries, see Querying metadata

Use Metadata to filter

The Unity Cloud Metadata package can be used to get a list of InstanceId that can then be provided to the DataStreamer to filter them out.