2 Creating an OpenUSD scene

 

This chapter covers

  • Crafting a USD scene using Python scripts and modules
  • Creating a stage with simple geometries
  • Importing and referencing assets and defining object layouts
  • Examining the different types of .usd file

Now, let’s walk through the process of creating and populating a USD stage. We'll start by exploring the fundamental elements of a USD stage, then begin creating a very simple scene containing basic geometries to understand the fundamentals of creating a .usd file and adding objects to the scene.

In practice, using pre-existing 3D models is far more common than relying on simple geometric shapes. These models are incorporated into a scene by referencing external files, which assigns them a place in the scene hierarchy. Later in this chapter, we’ll explore a more complex example: a kitchen scene composed of various objects. While we won’t create this scene, we’ll analyze its structure to illustrate the hierarchical relationships between objects (or prims) on a stage. This will highlight how objects can nest within one another, forming a parent/child relationship.

Having explored the theory of referencing, we'll put your newly acquired knowledge into practice by creating a concrete example of referencing assets. We’ll guide you through building a new USD stage, where you'll reference another .usd file that we’ve created and made available for you to download.

2.1 Building a Debut USD Scene

2.1.1 Viewing the Sphere

2.2 Exploring Stage Hierarchy

2.3 Importing Assets

2.3.1 Understanding References

2.3.2 Considering Directories & File Paths when Referencing

2.3.3 Using References

2.3.4 Using Payloads

2.4 Setting Stage Properties

2.5 Saving the Scene

2.6 Summary