e93c6e5f74
The `pxr::VtArray<T>` type is based on a copy-on-write scheme that is very easy to trigger unnecessarily because of how the C++ type system works[1]. Here we bypass unneeded copies by ensuring we always call the `const` version of various accessor functions. The offending call-sites were found by using the `VT_LOG_STACK_ON_ARRAY_DETACH_COPY` env variable. This yields a very small 2-3% performance benefit when loading in a typical, mixed-use, asset like e.g. the "4004 Moore Lane" scene. [1] https://github.com/PixarAnimationStudios/OpenUSD/blob/dev/pxr/base/vt/array.h#L139 Pull Request: https://projects.blender.org/blender/blender/pulls/136014