* Viewport: levels of detail for large meshes (#4724)
A large instanced mesh (20 k triangles or more) gets coarser copies, made
once on a worker (`mesh_lod`): a quarter, a sixteenth and a sixty-fourth of
its triangles, by quadric edge collapse (`geom::simplify`, after Garland and
Heckbert 1997; no fold-overs, no sheets joined, open boundaries kept), each
with its measured deviation from the full mesh. Each frame, as placements
are culled, each is drawn from the coarsest copy whose deviation stays
under 0.75 px where it stands (`placement_scale`, `level_for`). Until the
copies are made the mesh is drawn in full; the scene is built again when
they are. Display only: picking, measuring and exports keep the reference
mesh. Outside the kernel.
25 placements of a 2 M-triangle STL, 3600 x 2190 px, 4x MSAA, M2 Max
(`instanced_scene_gpu_benchmark`): 20.2 -> 1.2 ms a frame with all in
view, 21.9 -> 2.9 ms close up. The copies take 10 s to make, on a worker.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
* Viewport: see-through and faded parts drawn as instances (#4888)
See-through (an appearance's opacity) and faded (context around an active
component) bodies in one colour are drawn as instances like opaque ones,
their alpha in each placement's colour: one copy of the triangles, levels
of detail and culling, no per-placement copies built on the window thread.
Their placements are ordered back to front each frame (not their
triangles one by one) for devices that sort see-through surfaces.
The GPU benchmark gains `SOLIDCRAFT_BENCH_OPACITY` and the CPU share of
each frame, and its pictures each placement's own triangles too.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
* Viewport: order-independent transparency for see-through surfaces (#4734)
The model's see-through surfaces (glass, faded context; instanced or not)
were sorted back to front triangle by triangle on the window thread
whenever the view turned. They are now drawn with weighted blended order-
independent transparency (McGuire and Bavoil 2013): when there are any,
the frame is drawn into the renderer's own textures (as supersampling
does), the see-through surfaces gathered into a weighted colour and a
revealage target against the frame's depth, laid over the frame in one
full-screen pass, then the overlays drawn over them. Nothing is sorted.
A device that cannot blend into float targets keeps the sorted way.
25 placements of a 2 M-triangle STL at opacity 0.5, M2 Max, 3600 x 2190 px:
about 10 s a frame sorted, 21.6 ms (17.2 ms instanced, 2.8 ms with levels
of detail).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
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Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Jackson OurslandandClaude Opus 5.5
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