THREE.JS / FOUNDATIONS 338
Know your lanes.
Subgroups are not workgroups. Probe the device-dependent width, lane identity, reductions, ballot bits, broadcast, shuffle, and the feature gate that keeps those promises honest.
Initializing subgroup probe—
Waiting for the native WebGPU subgroup feature.
The probe is waiting for a compute dispatch.
- feature
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- subgroup width
- —
- subgroups
- —
- invariants
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- ballot
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- dispatches
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- readbacks
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Contract: one 128-lane native WebGPU workgroup, three GPU readback buffers, and no hard-coded subgroup width. The existing reduction lab studies algorithms; this route studies subgroup semantics and capability boundaries.
Native subgroup execution is unavailable here.No WebGL2 fallback is claimed; subgroup intrinsics have no equivalent GLSL path.
Subgroup probe failed.The native WebGPU probe could not initialize.
The route follows the official TSL, Renderer, and compute reduction surfaces.
LAB 338 / SUBGROUP CONTRACT