Import 3D Model

Status: Implemented

Import 3D Model feature dialog

Import 3D Model loads STL or 3MF data, optionally runs a mesh repair pass, and converts the triangles into one or more BREP.MeshToBrep solids.

Inputs

  • fileToImport – STL (ASCII or binary) or 3MF data supplied as a string, data URL, or ArrayBuffer.
  • deflectionAngle – face split angle in degrees used when converting the triangle mesh into analytic faces.
  • decimationLevel – percent of original mesh detail to keep before repair and face grouping (100 keeps original mesh).
  • meshRepairLevel – NONE, BASIC, or AGGRESSIVE passes through BREP.MeshRepairer.
  • centerMesh – translate the imported geometry so its bounding box center is at the origin before conversion.
  • extractMultipleSolids – when enabled, splits disconnected triangle islands into separate solids.
  • extractPlanarFaces – enables planar-region extraction before angle-based grouping.
  • planarFaceMinAreaPercent – minimum planar region size (percent of total mesh area) used when extractPlanarFaces is enabled.
  • segmentAnalyticPrimitives – when enabled, preserves existing face boundaries and refines each non-planar face independently using primitive segmentation (PLANE, CYLINDER, CONE, OTHER).

Behaviour

  • Strings are treated as ASCII STL unless the data begins with a base64 data URL; ArrayBuffers are inspected for ZIP headers (PK) to decide between 3MF and binary STL.
  • When a 3MF file is provided, all meshes in the archive are transformed into world space and merged into a single BufferGeometry before conversion.
  • The feature caches a solid snapshot in persistentData.importCache keyed by both source payload and import parameters so timeline rebuilds can skip reparsing.
  • The importer also caches the original parsed mesh payload and always reapplies decimation from that source mesh, so changing decimationLevel does not compound reductions across edits.
  • Setting decimationLevel back to 100 restores the same imported source geometry used before decimation.
  • extractMultipleSolids is optional; when disabled (default), the importer keeps the previous behavior and produces one solid. When enabled, disconnected triangle islands are emitted as separate solids.
  • Primitive segmentation is optional and controlled by a dialog checkbox; when enabled, the importer does not merge existing faces. Instead, it keeps current splits and only subdivides non-planar faces into smaller primitive regions.
  • No timeline or feature history is recovered from the source file.