# Tolerance

Configures tolerance settings of the document.

Absolute tolerance

  Specifies the maximum distance value that two points can be regarded as one same point.

Line zero

  Specifies the maximum distance value that two curves can be regarded as one same curve.

Relative zero

  Specifies the maximum distance value in the normalized `(0,1)` space that two points can be regarded as one same point.

Angle zero

  Specifies the maximum angle difference value in degree that could be regarded as zero angle.

Machine zero

  Specifies the smallest floating value to avoid zero division exception. Usually the user should not touch this setting.

Max ratio of knot spans

  Specifies the maximum ratio of neighboring two spans of a knot vector. Usually the user should not touch this setting.

Restore Defaults

  Reset unit properties to default values.