{
  "sources": [
    "tangency-labs/solidcraft#3730",
    "tangency-labs/solidcraft#3872"
  ],
  "what": "a block with a closed cavity written as BREP_WITH_VOIDS whose void shell (outward-facing faces) is turned by ORIENTED_CLOSED_SHELL .F.; the cavity must be taken out, not added",
  "source": "analytic",
  "method": "V = 40*30*12.5 - 20*6*5 = 15000 - 600; A = 2(40*30+40*12.5+30*12.5) + 2(20*6+20*5+6*5) = 4150 + 500; faces 6+6, edges 12+12, vertices 8+8; one body with two shells (outer and cavity)",
  "body_count": 1,
  "shells": 2,
  "volume_mm3": 14400.0,
  "area_mm2": 4650.0,
  "faces": 12,
  "edges": 24,
  "vertices": 16
}