Subdivision
USD's subdivisionScheme falls back to catmullClark, so a mesh that authors no scheme is a subdivision surface, and drawing its authored points directly is wrong in both silhouette and volume.
The levels
| Level | usdview complexity | Effect |
|---|---|---|
| Low | 1.0 | Draws the control cage exactly as authored. A mesh with a subdivision scheme renders faceted and slightly too small |
| Medium | 1.1 | Subdivides every mesh that carries a subdivision scheme |
| High | 1.2 | The same, at a higher refinement level |
| Very High | 1.3 | The same again |
Because USD falls back to catmullClark, that means every mesh that does not explicitly say none.
Setting the level
The default for stages opened from then on is set in Settings ▸ USD ▸ Subdivision, where Auto is offered alongside the four fixed levels.
The level for the stage already open is set in the Info tab's Refinement section, which appears only when the stage actually contains meshes that subdivide. That section offers the four fixed levels; a stage that opened under Auto can be moved off it there.
The face budget
Refinement multiplies geometry quickly: roughly sixteen times at High and sixty-four times at Very High. Solidly enforces a face budget derived from the Mac it is running on, and refines less when the requested level would exceed it.
When that happens the Refinement section reports it, either as the whole stage refined to a lower level or as a stated number of meshes refined less than the rest. Both notes name the budget for this Mac.
Counting refined geometry
The Info tab's Summary reports the counts of what is drawn, which after refinement are the refined counts. When refinement has changed them, an Authored Mesh Indices row reports the authored total alongside.
Implicit geometry, meaning a Sphere, a Cube, and the other gprims defined by parameters rather than by topology, contributes to what is drawn but has no authored count of its own, so it is not included in that row.