Creo Simulate > Modeling Structure and Thermal Problems > Meshes > Native Mode Meshes > Working with Geometry Tolerances > About Geometry Tolerance
  
About Geometry Tolerance
If your model fails to mesh when you run AutoGEM or an analysis, you may be able to fix the problem by working with the geometry tolerance settings for your model. Adjusting the geometry tolerance settings can help you eliminate such problems as small geometry, sharp angles, and negative angles that can hamper the creation of a precise mesh. Working with geometry tolerances is particularly useful for simplifying the geometry of models with large differences in scale. In addition, geometry tolerances determine whether Creo Simulate merges overlapping parts in a midsurface assembly or uses automatic midsurface connections.
Click Refine Model and then click the arrow next to AutoGEM. Click Geometry Tolerance, the Geometry Tolerance Settings dialog box opens, enabling you to specify several tolerance values such as Minimum edge length, Minimum surface dimension, Minimum cusp angle, and Merge tolerance.
Creo Simulate merges or removes geometry based on the tolerance values you specify, but the definition of the surrounding geometric entities remains unchanged.
In deciding new tolerance values, you should consider the effect you want to achieve. For example, if you find that a mesh fails because some of the edges in the model are too small for AutoGEM to correctly resolve, you might increase the minimum edge length tolerance value to ensure that AutoGEM could resolve the problem edges. However, if you find that AutoGEM merges away a surface sliver that you want to see results for, you might instead reduce the minimum surface dimension, forcing AutoGEM to acknowledge the surface. When adjusting tolerance values, bear the following in mind:
You should not enter extremely large values that may prevent the model from meshing or running an analysis.
Any changes you make to the tolerance values should not diverge significantly from the defaults in place when you open the Geometry Tolerance Settings dialog box. As a general rule, you should keep such changes within 10% of the defaults displayed in the dialog box.
If you enter erroneous values in any of the fields, you can reset the dialog box to the default values.
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