yhz5613813/cadflow/cadflow-validate-export

CadFlow Validation and Export

Use this skill as the final quality gate. It does not create geometry by itself; it verifies the result produced by a modeling skill and refuses unsupported or unmeasured claims.

Required validation sequence

1. Identify the artifact type: rigid Shape, replayable ModelResult, static

FlexibleMesh, or ContactSimulationModel. Record source script, environment, units, and output directory.

1. Validate geometry before export. For solids check validity, one-solid

topology, volume, area, bbox extents, and expected feature dimensions. For flexible meshes check finite arrays, index bounds, unit normals, triangle area, panel ranges, deterministic rebuild, and watertightness when thick.

1. If graph/model JSON exists, import and replay it independently. Compare

result count and measured geometry; do not trust only a successful parser.

1. Export requested files. Verify each file exists, is non-empty, has the

expected header/format, and can be parsed or reopened when a parser exists.

1. Render requested views. Check PNG signature, dimensions, non-zero content,

and that all requested views are present.

1. Write a concise report with pass/fail status, measured values, tolerances,

file sizes, and residual risks.

For a ContactSimulationModel, run its semantic validation and native analysis before exporting the package. Check every component/material/surface/law/pair reference, face BREP hash, assembly transform, oriented normal, initial gap, candidate count, and explicit unit string. Read references/checklists.md for the package gate.

Public boundaries

• Use import cadflow as cad.
• Use public cadflow.flexible for flexible meshes and public modeling,

serialization, and inspection APIs for rigid geometry.

• Use public cadflow.simulation for face-contact validation and package

export. Do not load the native library or OCP directly in user scripts.

• Do not repair a bad result by editing private native code during validation.
• Do not call a static mesh watertight merely because it renders; inspect edge

multiplicities and triangle orientation.

Rigid-shape gate

assert final_shape.validate().to_dict()["ok"]
assert final_shape.topology["solids"] == 1
assert final_shape.volume > 0.0
lower = final_shape.bbox[:3]
upper = final_shape.bbox[3:]
assert all(u > l for l, u in zip(lower, upper))

Query expected dimensions and tolerances explicitly. A valid shape with the wrong dimensions is a failed deliverable.

Flexible-mesh gate

import numpy as np
assert np.all(np.isfinite(mesh.vertices))
assert np.allclose(np.linalg.norm(mesh.normals, axis=1), 1.0, atol=1e-5)
assert int(mesh.triangles.max()) < mesh.vertex_count
points = mesh.vertices[mesh.triangles]
areas = 0.5 * np.linalg.norm(
    np.cross(points[:, 1] - points[:, 0], points[:, 2] - points[:, 0]), axis=1
)
assert float(areas.min()) > 1e-9
if any(panel.material.thickness > 0 for panel in mesh.panels):
    assert mesh.is_watertight

Export gate

For rigid shapes use export_step and export_stl. Export a 2D machining DXF only from the intended planar face, then verify every LWPOLYLINE is closed, outer and inner loop counts match the part, $INSUNITS is millimeters, and the profile bounds match the selected face. For flexible meshes use write_obj, write_stl, and write_json. Ensure the parent directory exists. Check STL triangle count and expected binary length when applicable:

import struct
with open(stl_path, "rb") as handle:
    handle.seek(80)
    count = struct.unpack("<I", handle.read(4))[0]
assert stl_path.stat().st_size == 84 + 50 * count

For PNG, verify the eight-byte PNG signature, width/height from the IHDR, and that the file is not an empty placeholder.

Reporting

Report exact paths and measurements. Separate:

• measured facts (counts, bounds, area, file sizes);
• assumptions (units, coordinate frame, inferred dimensions);
• validation status;
• unresolved risks (e.g. no physical cloth simulation, approximate folds, or

unsupported external CAD features).