Hydra Invalidation when updating Materials and Point Instancers

Community Hydra
1

Hey Hydra Experts,
We’re seeing Hydra being quite aggressive with the scene invalidation both with and without USDIMAGINGGL_ENGINE_ENABLE_SCENE_INDEX.

We’re seeing the following two issues with USD 24.3/24.5

  1. When we modify the topology of a material graph, it invalidates the material AND all prims that the material is assigned to. Which calls into the render delegates Create and Destroy methods for each.
  2. When we update the transform of a point instance, it invalidates the entire point instances. I see this is called out in pointInstancerAdapter.cpp in 24.11 as well. For example, just moving the instance around in space.

Is there any advice folks have for dealing with this aggressive invalidation? We’d like to keep our render updates minimal where possible.

2

As discussed, filing issues