Construction

These tools mutate scene bodies by applying features, spatial transforms, boolean set operations, and mirror/pattern operations. Reach for them when you need to modify existing geometry rather than author it from scratch — feature application and booleans both record topology history so remap_selection can carry selectionIds across the mutation.

Tools

• apply_feature · transform_body · boolean_op · mirror_or_pattern

apply_feature

Apply a single parametric feature (drill, fillet, chamfer, extrude, revolve, thread, or boolean) to a scene body via OCCTSwift’s FeatureReconstructor.

Server: Swift + Node

Parameters

Returns — Updated scene manifest. On failure, returns an error string describing what the feature reconstructor rejected.

Example

// tool call arguments — fillet every edge of "block" with radius 2 mm, in place
{
  "bodyId": "block",
  "feature": { "kind": "fillet", "radius": 2.0 }
}

// example result
{ "bodyId": "block", "inPlace": true, "outputPath": "…/block.brep" }

Notes — The feature object is a FeatureSpec keyed by a kind discriminator. The decoded kinds and their fields (note snake_case keys — this is the JSON the reconstructor decodes, not the Swift labels):

apply_feature records per-feature topology history (via BuildResult.histories[id]) so remap_selection can map selectionIds from the input body onto the output. An unrecognised kind (or one whose geometry the reconstructor rejects) returns no shape with a skipped reason.

Drives — OCCTSwift.FeatureReconstructor; occtkit reconstruct (Node).

transform_body

Apply translate, rotate, and/or uniform scale to a scene body.

Server: Swift + Node

Parameters

Returns — Updated scene manifest reflecting the moved/scaled body.

Example

// tool call arguments — move "bracket" 50 mm along Z and rotate 90° around Z
{
  "bodyId": "bracket",
  "translate": [0, 0, 50],
  "rotateAxisAngle": [0, 0, 1, 1.5708],
  "outputBodyId": "bracket_placed"
}

// example result
{
  "bodies": [
    { "id": "bracket", "name": "Bracket" },
    { "id": "bracket_placed", "name": "Bracket (placed)" }
  ]
}

Notes — Multiple transform parameters may be combined in a single call; they are composed in the order translate → rotateAxisAngle → rotateEulerXyz → scale. transform_body is a rigid/similarity transform and preserves topology 1-to-1, so remap_selection resolves any selectionId on the original via the implicit identity path (no history record is written).

Drives — OCCTSwift.Shape.transformed; occtkit transform (Node).

boolean_op

Boolean set operation (union / subtract / intersect / split) between two scene bodies. The result is always added as a new body.

Server: Swift + Node

Parameters

Returns — Updated scene manifest. Errors from OCCT (non-manifold inputs, no intersection, etc.) are returned as an error string.

Example

// tool call arguments — subtract a hole body from a plate
{
  "op": "subtract",
  "aBodyId": "plate",
  "bBodyId": "hole",
  "outputBodyId": "plate_drilled",
  "removeInputs": true
}

// example result
{
  "bodies": [
    { "id": "plate_drilled", "name": "plate_drilled" }
  ]
}

Notes — boolean_op records full per-input topology history (via OCCTSwift *WithFullHistory variants) under the output body and both inputs. This means remap_selection can map a selectionId that lived on either aBodyId or bBodyId onto the result body.

Drives — OCCTSwift.Shape boolean operators (+, -, &, split); occtkit boolean (Node).

mirror_or_pattern

Mirror a body through a plane, or create a linear or circular pattern, producing a single (possibly compound) new body in the scene.

Server: Swift + Node

Parameters

Returns — Updated scene manifest with the new pattern body added. For mirrors, the mirror plane is written to provenance.json in the output directory so find_correspondences can recover the transform automatically.

Example

// tool call arguments — mirror "fin" through the XZ plane (Y=0)
{
  "bodyId": "fin",
  "kind": "mirror",
  "params": {
    "planeNormal": [0, 1, 0],
    "planeOrigin": [0, 0, 0]
  },
  "outputBodyId": "fin_mirrored"
}

// example result
{
  "bodies": [
    { "id": "fin", "name": "Fin" },
    { "id": "fin_mirrored", "name": "fin_mirrored" }
  ]
}

Notes — mirror_or_pattern produces new bodies rather than mutating in place, so remap_selection does not apply across source → copy. Use find_correspondences instead: for mirrors it reads the provenance transform automatically; for linear/circular patterns supply the instance transform explicitly (provenance is not written for multi-copy patterns).