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The Repair/Refinement page lets you define various visual parameters for the translation of native CAD files.

This page discusses:


Refinement settings determine how Composer tessellates (meshes) the model, which affects model accuracy.

Set these options to achieve the best compromise between accuracy and file size.

Command Name Description

Specifies the triangulation method:

  • Chordal error - All geometry has the same chordal error. Chordal error is the distance between the triangles that define the geometry in Composer and the edges of the original geometry. When you move the slider to high quality, you decrease the chordal error and increase the quality of the assembly.

    In this image, the black circle is the original geometry. The blue triangles define the geometry in Composer. The chordal error is the distance represented by the red arrows.

  • Normal deviation - All geometry has the same normal deviation. Normal deviation is the angle between the normals of the edges that define the triangular geometry of Composer. When you move the slider to high quality, you decrease the normal deviation and increase the quality of the assembly.

    In the image, the black circle is the original geometry. The blue triangles define the geometry in Composer. The normal deviation is the angle between the red arrows.

The difference between these two triangulation methods is visible for scenes containing geometry of various sizes. Consider an assembly of one very large cylinder and one very small cylinder.

With Chordal error, because the chordal error is constant, the polygon inscribing the large cylinder has many more sides. This results in the geometry of the large cylinder looking better than the small cylinder.

With Normal deviation, because the normal deviation is constant, the polygons inscribing both cylinders have the same number of sides. This results in the geometry of the small cylinder looking better than the large cylinder.

You can optimize the geometry degradation by moving the slider between high quality (for optimum triangulation quality), medium, and low quality.

Absolute (Advanced users only, use carefully)

Defines the triangulation approximations.

Important: This option is recommended for expert users only. Configuring absolute refinement is time consuming and should be used only when relative refinement produces unacceptable results.

You can set these three parameters independently. When you set more than one, their effects are combined.

  • Chordal error - Variation in millimeters between native geometry CAD and the tessellated model.
  • Normal deviation - Angle formed between the normals of the triangle faces.
  • Edge length - Length of the triangle edges in millimeters.

    Note: Not considered for SOLIDWORKS files.

For each parameter, specify values that define the maximum limits.

Enable auto repair (healing is time intensive) Checks for missing triangles, incorrect holes in the mesh, extra faces, and other discontinuity issues, and attempts to repair problems by adding triangles. This option degrades import speed, so use only when tessellation is poor. To import files without checking for incorrect geometry, clear this option.


Occlusion removes parts from the model based on size or whether the parts are internal and therefore not visible.

Original Model Internal Parts Detected

Command Name Description
Remove small parts Removes parts smaller than the specified percentage of the total scene size. The calculation uses the volume of a bounding box, not the actual part volume. For example, if you specify 10%, only parts that fit in a bounding box that is 10% of the entire scene are removed.
Remove internal parts Removes parts that are internal and therefore not visible. Applies to .smg, .smgXml, or .smgProj files only.
Apply to (Available when Remove internal parts is selected.) Runs occlusion on:
  • Loading View
  • Views
  • Animation
  • All
Note: Actors with opacity, displacement, or texture-with-transparency property keys are not considered for occlusion.
3D (Available when Remove internal parts is selected.) Performs occlusion on the 3D model. Snapshots are taken from different points of view. For animation mode, snapshots are taken along the camera animation. Select one of the following:
  • Speed - Uses fewer camera positions resulting in faster computation.
  • Quality - Uses more camera positions.
To perform occlusion on the 2D view, clear this option.
Cut triangles (Available when Remove internal parts is selected.) Runs occlusion on actor triangles instead of actors. After analysis, you can remove hidden triangles. Outlines remain visible until the file is reopened.
Create Selection Set of Occluded Actors Creates a single selection set composed of all the occluded actors.
Note: This option lets you check your result manually in Composer after the conversion.
Remove Occluded Actors Deletes the occluded actors from the resulting Composer file (output file).
Important: This operation cannot be undone. Once the occluded actors are deleted from the output file, you will have no way to retrieve them.

SMG output

These options affect saved Composer files.

Command NameDescription
CompressionSets the amount of compression in files, which affects model tessellation quality.
  • Low (high quality) - 32 bytes/point, high measurement quality, large file
  • Medium - 16 bytes/point
  • High (low quality) - 8 bytes/point, low measurement quality, small file
The compression algorithm uses a bounding box defined by its coordinates: xmin, xmax, ymin, ymax, zmin, zmax. This bounding box is subdivided into a number of cubes according to the quality of compression selected:
  • Low (high quality): 2^32 * 2^32 * 2^32
  • Medium: 2^16 * 2^16 * 2^16
  • High (low quality): 2^8 * 2^8 * 2^8
All tops (xi, yi, zi) of the triangulation are laid out on the tops of the cubes contained in the bounding box.

When saving a file with medium or high compression, you should consider the following:

  • You cannot return to original quality. You must re-import your CAD files if you want to do so.
  • Medium or high compression affects geometry precision. In the case of large parts where most of the precision is taken by the position of the object, little precision is left for elements such as small faces, lines or vertices.
  • Medium or high compression might cause display issues (such as small holes visible in the mesh of a part, overlapping faces, z-fight, appearance of undesired lines in technical illustration, etc.) in vector output generated by the Technical Illustration workshop.

To make it short, if geometry precision matters to you, it is recommended to use the Low (high quality) option.

Write normalsSaves normal directions for all faces in the file. Composer needs this information to display the outward or outside faces of parts and assemblies. When selected, file size is larger but file load time is shorter because Composer does not have to calculate this information. A normal to a flat surface is a three-dimensional vector that is perpendicular to the surface. A normal to a non-flat surface at a point "p" on the surface is a vector that is perpendicular to the tangent plane to that surface at "p".
Number of level of detailSpecifies how many levels of detail (LODs) are created and saved in .smgGeom files for each geometry actor during translation. LOD specifies the actor mesh detail. For example, a screw can have a lower LOD in a car context than in an engine context. This option works with the Relative refinement option; the LOD value is the Relative slider value divided by the LOD number:
  • 1 - Creates one LOD using the Relative slider value.
  • 2 - Creates two LODs. For example, if Relative is 0.8, the two LOD values are 0.8 and 0.4.
  • 3 - Creates three LODs. For example, if Relative is 0.8, the three LODs are 0.8, 0.4, and 0.26.
  • Number of level of detail is ignored when the Merge file into one actor per part import option is selected.
In Composer, the Use level of detail option ([Default] Document Properties - Project) specifies what LOD to use when opening a project. You can also load individual parts specifying LOD; in the Assembly tree, right-click a part and select Product > Load Products (Choose LOD).

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