File Types and Characteristics

3D scanners produce what is know as a point cloud these files are the bases of 3d scanning and are used to generate the three different file types, surface wrap, hybrid surface model, and parametric model.

Point Cloud

Scan data produces point clouds which are converted into a mesh or polygon file. These files can be used for inspection, animation gaming and are the base data for reverse engineering.

Characteristics

  • Captures points of the as built component
  • Includes manufacturing defects
  • More points = more definition
  • Used in gaming
  • Most cad programs do not support
  • STL, OBJ, 3DS, PLY

Surface Wrap

Refers to the way in which 3D scanning software like Geomagic, RapidForm, fit mathematical IGES surfaces to a “physical” scan. Similar to how plastic shrinkwrap “shrinks” down onto a part being “wrapped”.

Characteristics

  • Captures as-built state
  • Includes manufacturing defects
  • Patch-work of small surfaces
  • Non Class A surface finish
  • Requires STL file

Hybrid Surface Model

An IGES or STEP surface that usually combines auto-surfaced features with typical 3D modeling operations. Hybrid models are “dumb” because the data contains no parametric history of the model; it is simply a surface that cannot be intelligently edited. Such models have areas that are not ideally mathematical in nature, and instead are composed of NURBS surface estimates of the scan data

Characteristics

  • Ideal data converted from scan data
  • Can ignore or incorporate manufacturing defects
  • “Dumb” IGES surfaces or solid
  • Modifications require re-trimming
  • Can be Class A surfaced

Design Intent Model

Data set that retains the history of how it was designed, so that modifications update all downstream features. Exchange of such models is supported by IGES. SolidWorks is a software program that is popular for creating and modifying parametric models

Characteristics

  • Ideal data converted from scan data
  • Can ignore or incorporate manufacturing defects
  • Parametric solid model
  • Modify model parametrically
  • Can be Class A surfaced