File Optimization

The platform automatically performs 3D model optimization during the upload.

Parametric File Formats

Parametric file format such as “.stp“ and “.iges“ contain surface representations of a 3D model. Although this representation provides an extremely precise and compact description of the model, it are not suitable for 3D printing. Our platform automatically converts surface representations into a triangular meshes and proceeds with mesh optimization.

Mesh File Formats

A mesh is a triangulated approximation of a 3D surface and it is a suitable representation for any 3D printer on the market. The most common mesh file formats are “.stl“, “.wrl“ and “.obj“. A mesh file does not require any pre-processing and is immediately suitable for mesh optimization.

Mesh Optimization

Mesh optimization will automatically start after the upload of a mesh file or the upload and the conversion of a parametric file.

Goal

The goal of mesh optimization is to ensure that your file is printable and that the outcome has the best possible quality. The platform will attempt a first optimization step to make sure your model meets the minimal requirements for printability and then starts a second optimization step to improve the surface quality of the final printout.

Minimum requirements for printability

Printers of several manufacturers will reject the 3D model if the following requirements are not met:

• Manifoldness or Watertightness:
  Manifold meshes are characterized by strong connectivity. In simple words, each triangle of a mesh should be connected to exactly 3 neighbor triangles.
  Strong connectivity guarantees that none of the following problems occurs:

  • Holes

    

  • Redundant triangles

    

  • Merged objects

    

• Correct triangle orientation:
  Meshes with correct triangle orientation uniquely define the inside and the outside of the object. If this requirement is not met, printers may not be able to correctly distinguish between printing volume and empty space. Triangles with incorrect orientation (in black) may also not be visualized incorrectly by CAD programs.

  

Requirements for best surface quality:

• Absence of intersections:
  For a high quality printout, the volume of each object needs to be uniquely defined, but self intersecting objects may define the same volume multiple times .

  

  Although many printers accept files with self intersections, the surface quality of the final printout may be negatively impacted.