Overview

The UsdMedia domain provides ways to associate various forms of media, such as audio (SpatialAudio) or thumbnails (AssetPreviewsAPI) with assets.

Working With Media

SpatialAudio allows for ambient audio playback or audio playback from a specific location. It also allows setting various playback options.

AssetsPreviewsAPI allows for setting one or more thumbnails for an asset. The thumbnails could be pre-rendered images of the asset that could be presented in the asset browser of a DCC tool, or in a system asset browser.

The following example, assetPreviewsApi.usda, uses both of these schemas.

#usda 1.0
(
    defaultPrim = "World"
    endTimeCode = 2400
    startTimeCode = 0
    timeCodesPerSecond = 24
)

def Xform "World"(
    prepend apiSchemas = ["AssetPreviewsAPI"]
    assetInfo = {
        dictionary previews = {
            dictionary thumbnails = {
                dictionary default = {
                    asset defaultImage = @defaultThumbnail.jpg@
                }
            }
        }
    }
)
{
    def Cube "Cube"
    {
        double3 xformOp:translate = (1, 5, -2)
        uniform token[] xformOpOrder = ["xformOp:translate"]

        def SpatialAudio "Speech"
        {
            uniform token auralMode = "spatial"
            uniform timecode endTime = 480
            uniform asset filePath = @mySpeech.mp3@
            uniform token playbackMode = "onceFromStartToEnd"
            uniform timecode startTime = 240
        }
    }

    def SpatialAudio "Ambient"
    {
        uniform token auralMode = "nonSpatial"
        uniform asset filePath = @myAmbientTrack.mp3@
        uniform token playbackMode = "loopFromStage"
    }
}

The following can be observed from the example above:

• The difference between using spatially played audio in Speech and nonSpatial audio in Ambient

• The way thumbnails are associated with assets, and how they can be utilized.

• The way Speech is nested under the Cube gprim, in case the gprim is ever moved or animated.

As an example of how the thumbnail information might be presented, the following macOS screenshot shows assetPreviewsApi.usda in the Finder file browser. Notice how Finder is using defaultThumbnail.jpg in the file icon for assetPreviewsApi.usda.