Webcutting facet-based geometry

We received the following on the support email. With permission and I am reproducing it here.

Dear Coreform team,

I am trying to perform a webcut operation on the volumes generated from facet file. After turning on developer commands using set dev on, when I try to perform the webcut operation, it causes Cubit to crash.

Could you please help me overcome this issue? My file is attached herewith, I am importing it with stitch and merge option.
model_c.zip (383.9 KB)


As you have noted, there are limited operations that work on facet-based geometry in Cubit. We would prefer to have CAD based geometry in most cases. This could come from a STEP file or an ACIS file or one of the paid CAD translators.

For simple facet-based geometry it is not difficult to rebuild it as ACIS geometry in Cubit. This is the approach that I recommend if you want to add arbitrary webcuts to the model.

Here is an example of rebuilding your part in Cubit and applying a hex mesh on it.


import stl "./model_c.stl" feature_angle 135.00 merge
create vertex location vertex all
delete volume
create surface vertex 31 30 48 47 42 27
create surface vertex 48 46 47
create surface vertex 50 46 40 41 42
sweep surface all perpendicular distance 200000
delete vertex all    # clean up construction vertices
imprint all
merge all
mesh volume all
draw hex all

For some geometries you might be able use the facet-based geometry and add partition lines to manually add the imprints so that surfaces will merge. Here is an example for that case. Note that in this case I also modified the feature angle on import so that the surfaces will be separated into distinct entities. This made it so I only had to partition one surface.

import stl "./model_c.stl" feature_angle 150 merge
draw volume 1 3
partition create surface 4 curve 36
merge all
mesh volume all
draw hex all

If a surface has a complex geometry, but a simple topology, you can use the answer given in How to convert a facet file to an ACIS file - Coreform Cubit - Coreform LLC For geology models, you have to recreate simple bounding geometries and use the create net surface approach for the complex geometries.