Usd is the core client-facing module for authoring, composing, and reading Universal Scene Description. USD is designed to encode scalable, hierarchically organized, static and time-sampled data, for the primary purpose of interchanging and augmenting the data between cooperating Digital Content Creation applications.
Core API Manual
This manual contains the API documentation for the core Usd module, prefaced with an introduction to the key concepts behind the API, and including a guide to making effective use of the API. In this manual we do not deeply explore the composition semantics that underly Usd scenegraphs - that is the domain of the (forthcoming) Universal Scene Description Composition Compendium. We will discuss some aspects of the composition operators, primarily as they affect authoring workflows and/or scalability and/or import/export.
UsdStage owns the scenegraph and provides access to a composition. UsdPrim is the hierarchically nestable unit of scene description. UsdAttribute records time-varying data on prims. UsdRelationship records links to other prims and properties. UsdEditTarget allows editing of any layer/variation contained in a stage. UsdNotice contains notifications that Usd issues when a stage's contents change. UsdSchemaBase is the base class for generated schema classes. UsdTimeCode is an ordinate that can be floating-point or an unvarying 'default'.