InStep - Help
Onshape Import/Export & File Explorer
The import of CAD and PartStudio files into InStep requires tesselation (conversion to triangle data). The 'resolution' of this tesselation can be modified from the settings (the small button with a gear and spanner shown at the bottom left of the main Onshape window).
The available settings are:
- Angle Tolerance
- This sets the angular tolerance along curvature. Basically, if a surface has small radii in features such as blends and holes, having a small angle tolerance will increase the amount of detail that is preserved by increasing the number of triangles generated in these locations. It is recommended that this number is initially kept high and the result observed and adjustments made if necessary.
- Chord Tolerance
- Chord tolerance is similar in to angular tolerance but rather than considering the angle, it considers the (maximum) deviation of the newly formed straight line from the original surface. A smaller chord tolerance will generate more triangles and should be increased only if the result shows unacceptable levels of detail.
- Maximum Face Width
- Defines the maximum width that a triangle can contain. This value should generally be set quite large to prevent too many triangles from being formed on planar surfaces which do not provide additional detail in the resultant data.
- Minimum Face Width
- Defines the minimum width that is provided. This setting works in contrast to the Chord and Angle tolerance values and should generally be set to account for the smallest edge lengths expected.
- Compress STP Upload
- This setting determines whether the data to be uploaded (only applicable to uploading in the STP format) is to first be compressed into a ZIP archive and then transmitted as such or whether the file is to be sent 'raw'. Uploading as a ZIP file will always be faster since there is far less data to send (usually on the order of 80% less) but can cause issues if the compression/decompression encounters unforeseen issues. It is suggested that this option is only turned off if issues arise.