6 Making an OpenUSD animation
This chapter covers
- Setting up animation on the stage
- Playing with Xform and property animation
- Composing animation clips
We have learned how to create a stage, populate it with objects, beautify it with materials and lighting, and make use of cameras to capture our creations. These skills are ample if we only wish to create static images from our scenes, but what if we want to set the scene in motion?
First we need to introduce the fourth dimension of time by applying a timeline to our stage. OpenUSD provides us with all the necessary tools through its UsdStage and UsdTimeCode classes which build on traditional time-based media concepts, allowing for additional flexibility across different platforms. We'll examine this essential aspect of animation and see how it sets the stage for dynamic motion.
Once we have our timeline in place, we can start defining the movement and transformation of objects, lights, and cameras. By assigning values to properties at specific moments in time, we create keyframes that control the timing and extent of the animation. We’ll also explore how to smooth out our animations, using interpolation to fill in the frames between keyframes.