DMAUDITLEVEL system variable
DMAUDIT command, level of detail
Controls the message types displayed for the DMAUDIT command.
BricsCAD only
| Type: |
Short |
| Saved in: |
Workspace |
| Range: |
0 to 3 |
| Default value: |
1 |
| Possible options: |
1: Ignore dynamic range errors 2: Ignore sliver faces |
- Dynamic range
- The dynamic range is the range of lengths required to create valid geometry. The range is limited because a modeler expresses the coordinates of points in 3D-space in terms of double precision floating point numbers. To represent a number, floating point numbers use a finite number of significant digits, which in the case of double precision numbers is roughly fourteen to sixteen significant digits. The modeler's use of digits is limited to nine significant digits to avoid susceptibility to round-off error. This means that a model's dynamic range can only be nine orders of magnitude wide. Thus, the ratio of the longest to shortest length that can be modeled is 10^9.
The numbers could be interpreted as inches, millimeters, or any other unit. The modeler has a resolution of 10^-6, which means that if the distance between two points is less than that, they are considered to be the same. A guard band of at least one order of magnitude around the resolution value is also required. For practical reasons, there can be ambiguity about distances that are close to the resolution value, so this guard band is a safety margin to improve reliability.
As a result, the valid dynamic range of models in BricsCAD® is 10^-5 to 10^4 and is not unit dependent. The dynamic range of parts modeled in millimeters is 0.00001 mm to 10000 mm. The dynamic range of parts modeled in meters is 0.00001 m to 10000 m.
If the dynamic range is exceeded, the behavior of modeling algorithms is unpredictable. This may cause modeler algorithms to produce incorrect results or failures.
- Sliver face
-
Some models may contain long narrow faces that were not intended to be present in the design of the model. Typically, these occur in imported models due to the tolerance differences between geometric modeling systems.
Because the size of a feature cannot be smaller than the resolution of a modeler, genuine faces are at least an order of magnitude larger than the maximum gap in the model. Any face smaller than that is a candidate for being spurious.
The entity's tolerance is calculated as the highest tolerance value among the entity's tolerant edges and vertices.
The maximum distance between the long edges of such a face is smaller than the specified tolerance. It has at least one short and no more than three long edges. A short edge is an edge that is shorter than the specified tolerance. A long edge is longer than the specified tolerance. The tolerance can be calculated automatically based on the entity's bounding box.
Because the dimensions of sliver geometry are close to the modeler resolution, performing operations on it is difficult. Because such geometry isn't usually intended, it is attempted to be replaced with tolerant geometry. In bodies, tolerant edges replace sliver faces, and tolerant vertices replace short edges. When fixing manually, slivers can be removed and adjacent faces extended if needed.