Float Tolerance

Float Tolerance

Originally Posted: 

Wednesday, August 3, 2022

Last Updated: 

Wednesday, August 3, 2022

Software/Versions Affected:

  • THERM›7

The float tolerance is used throughout the program. When trying to mesh a file, it is used to determine how close points can be to each other and still be considered distinct points.

The float tolerance values can be set by going to the Optics / Preferences menu, and then the Therm File Options tab 

  • In THERM 7.4, a default value for float tolerance is included in the THERM INI file and it is set to 0.02 mm. That means that in some cases where the file wouldn't mesh properly, the only solution is to modify the geometry of the file.
  • In THERM 7.8, we decided that it would potentially be useful to users to be able to modify the Float Tolerance value to see if a file could be meshed without modifying the geometry. Therefore, we brought the Float Tolerance setting into the User Interface in the Options / Preferences menu, Therm File Options tab. For a new file, the program still starts with the default (from the INI file) of 0.02 mm. But the user can change that value if needed, and in this case the new value is saved with the THERM file and the THERM INI value is NOT changed; it still remains at the default value of 0.02 mm.
  • Here are some recommendations about how changing the Float Tolerance could be used:
    • The values for float tolerance should only be the following: 0.01 mm, 0.02 mm, and 0.03 mm. Values smaller or larger than those are not recommended.
    • Gaps in a mesh: If, when the program tries to mesh a file, there are areas that are not meshed, it might be useful to try decreasing the Float Tolerance in 0.01 mm increments (still staying within the 0.01 mm - 0.03 mm range). For example:
      • If the file float tolerance is 0.03 mm, and there is a gap in the mesh, change to 0.02 mm, and if it meshes, you are done.
      • If there is still a gap in the mesh, try reducing the value to 0.01 mm, and if it meshes you are done.
      • If it still doesn't mesh, set the Float Tolerance back to 0.02 and work on changing the geometry to allow the mesh to be generated properly.
    • Points closer together than the program tolerance: If the program says that points in the model are closer together than the program tolerance, and/or the program indicates a need to simplify the geometry, check the file float tolerance. Try increasing the float tolerance between 0.01 mm, 0.02 mm and 0.03 mm. If this doesn’t fix it, change the Float Tolerance back to 0.02 mm and work on changing the geometry to allow the mesh to be generated properly.
  • If a user does not want to bother tweaking the Float Tolerance when trying to mesh a file, there is always the option of keeping the default value of 0.02 mm and adjusting the geometry, which emulates the behavior in THERM 7.4.