The first hover over a large body made two things in the frame: the body's
pick index (its triangles and edges in hierarchies; about 0.3 s for a long
modelled thread, a quarter of a million triangles) and, with the GPU viewport,
the plan mesh a highlighted face is drawn from (about 0.7 s for the same
thread). The window froze for the sum.
A large mesh's pick index is now made on a worker, and picks scan the mesh
until it is there (a few milliseconds); a body's plan mesh is made on a worker
too (`ModelBody::plan_mesh_soon`), and until it is there the hovered face is
lit on the mesh the viewport already has. Small meshes, and the browser build,
make both at once as before.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
bherbruck
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