On an edge_split adapt child with a steep grading — base 0.2/refinement=1 (h ~0.1) adapted to h=0.04 over a 0.15 ramp, 2 levels — place_sheet's volume-conservation gate refuses: "the placement changed the domain volume: 1.0 -> 1.000169377538". The drift is identical to 12 digits with a coarse verbatim sheet (0.1 spacing) and with the same sheet resampled via size=0.04, so it is a property of the cavity against the graded transition shell, not of the sheet triangulation.
The fault-network route's gentler law (band 3h, ramp 10h, h=0.06 from a 0.12 base, clearance 0.8) builds cleanly at 85k cells, so the working window exists; the failing configuration is legal input and should either build or refuse with the offending feature NAMED (the pinch-naming diagnostic pattern). Reproduction: ~/+Simulations/place_route_health/contrast_solve_tail.py history (the steep-grading variant is recorded in the README).
The gate itself behaved correctly — it caught a genuinely mis-built fill. The defect is upstream: carve/fill on a cavity whose wall spans a sharp size transition.
Underworld development team with AI support from Claude Code
On an edge_split adapt child with a steep grading — base 0.2/refinement=1 (h ~0.1) adapted to h=0.04 over a 0.15 ramp, 2 levels — place_sheet's volume-conservation gate refuses: "the placement changed the domain volume: 1.0 -> 1.000169377538". The drift is identical to 12 digits with a coarse verbatim sheet (0.1 spacing) and with the same sheet resampled via size=0.04, so it is a property of the cavity against the graded transition shell, not of the sheet triangulation.
The fault-network route's gentler law (band 3h, ramp 10h, h=0.06 from a 0.12 base, clearance 0.8) builds cleanly at 85k cells, so the working window exists; the failing configuration is legal input and should either build or refuse with the offending feature NAMED (the pinch-naming diagnostic pattern). Reproduction: ~/+Simulations/place_route_health/contrast_solve_tail.py history (the steep-grading variant is recorded in the README).
The gate itself behaved correctly — it caught a genuinely mis-built fill. The defect is upstream: carve/fill on a cavity whose wall spans a sharp size transition.
Underworld development team with AI support from Claude Code