Performance and behaviour findings in Bevy 0.19 against 0.18, with stock repros
RenderDiagnosticsPluginVersions: 0.19.1.
With RenderDiagnosticsPlugin, 0.18.1 reports a GPU time per shadow
view (render/shadow_directional_light_0_cascade_0/elapsed_gpu and so
on, and shadow_point_light_N_±axis for point lights). 0.19.1 reports
none: the shadow pass opens a tracing span
(bevy_pbr/src/render/light.rs:2880) but records no diagnostics span, so
the shadow maps’ GPU time is missing from the totals.
repros/shadow-cameras --shadows hi: 0.18.1 lists four
shadow_directional_light_0_cascade_N rows (0.12 to 0.72 ms of GPU each
for the spheres); 0.19.1 lists main_opaque_pass_3d, clustering,
upscaling, early_mesh_preprocessing, bin_unpacking and no shadow
rows at all, with the same shadows on screen.
This is what made finding 1 hard to see: the cost was there in the frame time but not in any pass.