LAB 157 / PARALLEL SCAN

Find the next active index.

Turn sparse particle flags into stable dense positions with workgroup scans, then feed the resulting count into an indirect compute dispatch.

—Preparing

Studying hierarchical prefix sums and compact work.

LIVE PARAMETERS

Shape the sparse field

Time scale 1.00 Activity threshold 0.52 Motion field 0.42 Pause marking and scan

The scan uses two workgroup-local ping-pong arrays, a second workgroup for block offsets, and a stable scatter. Count readback is opt-in; indirect dispatch does not need to return to JavaScript.

Source particles—

Active list—

Workgroups—

Compute passes—

Draw calls—

Tracked storage—

The route will identify the active backend and scan strategy.

Benchmark: not run

GPU count readback: not requested

RUNTIME ERROR

Find the next active index.

Shape the sparse field

The prefix scan could not start.