When expressing an opinion within a layer, it is possible to “redefine” a previously defined value of the property being edited. This mechanism is known as overrides because you are overriding what was there before. However, it is very important to note that the original data remains unchanged. The override only exists within the layer where you are defining it

This is by far the most important aspect to understand about USD. Opinions and their “value resolution” (resolving which value gets applied in the end) are key to the entire composition mechanism.

Below is a simple example of overriding a previously defined attribute’s opinion.

override example


  1. Shows cube_sphere_torus.usda where an attribute’s opinion is first authored (/GEO/Cube.size)
  2. Shows referenced.usda where
    • The layer cube_sphere_torus.usda is brought into the layer referenced.usda via a composition mechanism called referencing
    • An opinion is expressed on the already defined attribute /GEO/Cube.size, but in context of cube_sphere_torus.usda, essentially overriding what was there before
  3. Shows the composed final result, aka the stage