STL Export Failure

Coreform Cubit
#1

Coreform Cubit 2021.3
Fedora Core 33

I have the following error on export from Cubit

Cubit>export stl "/home/adavis/prod/patterson/simple/muchos_lattice.stl" overwrite

No entities (mesh or geometry) were specified. All bodies in the model will be exported to the STL file.

Writing facets to STL file...

ERROR: In AcisQueryEngine::get_graphics_facets

Acis unable to generate facets for body.

distance_tolerance = 0.000000

max_edge_length = 0.000000

normal_tolerance = 15

ERROR: ACIS API error number 35000

ACIS API message = Edge tolerances not met because max_grid_lines is set too low

ERROR: Write of Body 1694 FAILED.

Finished Command: export stl "/home/adavis/prod/patterson/simple/muchos_lattice.stl" overwrite```

It is a fairly atypical geometry, but AFAIK all valid CAD geometry.
#2

My guess is that you have a surface that is very small or at the very least a curve on a surface with a length of 0 within a tolerance of 1e-12.

Try analyzing body 1294 with the geometry power tool and see if it identifies the problematic small surfaces or curves. We recommend either removing or compositing the surfaces rather than trying to fix small curves first.

It is likely that volume 1294 and body 1294 are the same entity. On the chance that they are not, I suggest invoking the geometry power tool using “in body 1294” as shown in the image below.

image

You could also try creating a triangle surface mesh on body 1294 and see if the mesher can resolve the surfaces the ACIS faceter cannot.

surf in body 1294 scheme trimesh
mesh surf in body 1294

Watch for errors messages.