Question: Is there function like polytrim in part workbench?

[hummingnoise]

Hi All,

I imported an stp file of a part. Currently, I tesselate the shape to create the meshed version. Then, I use polytrim function to manipulate the edges of the part (basically for trimming some edge points).

I was wondering whether there is an equivalent function for trimming in any other workbenches, so I dont have to tesselate the part. Sorry if this is a stupid question. I am still new to Freecad

Best,
Baris

[onekk]

if you have a solid, it is difficult to manipulate edges as they define solid boundaries.

Probably as the name tell polytrim will work on polylines in FreeCAD (FC) they are called wires and wires are composed by edges.

You could manipulate almost all the entities in FC, but obviously you have to do it following some order:

I will try to point you to some explanations as wiki documents, and forum posts:

The following are general wiki post about different object in FC note that only DocumentObjects and Meshes are visualized, TopoShapes are the Solids that will go in a DocumentObject, but it is better to have in mind the distintion between them.

Document Objects
https://wiki.freecadweb.org/App_DocumentObject

TopoShapes
https://wiki.freecadweb.org/Part_TopoShape

Mesh
https://wiki.freecadweb.org/Mesh

This is an interesting post about Topology elements:

https://forum.freecadweb.org/viewtopic. ... 89#p500989

This post although is specific to Scripting and Python, has some interesting informations if you try to follow the posts about a topology is made.

edges >> wires >> faces >> shell >> solid

https://forum.freecadweb.org/viewtopic. ... 55#p484455

Some explanation similar to the above post are in this wiki page:

https://wiki.freecadweb.org/Topological_data_scripting

Geometry

The geometric objects are the building blocks of all topological objects:

Geom Base class of the geometric objects.
Line A straight line in 3D, defined by starting point and end point.
Circle Circle or circle segment defined by a center point and start and end point.
Etc.


Topology

The following topological data types are available:

Compound A group of any type of topological objects.
Compsolid A composite solid is a set of solids connected by their faces. It expands the notions of WIRE and SHELL to solids.
Solid A part of space limited by shells. It is three dimensional.
Shell A set of faces connected by their edges. A shell can be open or closed.
Face In 2D it is part of a plane; in 3D it is part of a surface. Its geometry is constrained (trimmed) by contours. It is two dimensional.
Wire A set of edges connected by their vertices. It can be an open or closed contour depending on whether the edges are linked or not.
Edge A topological element corresponding to a restrained curve. An edge is generally limited by vertices. It has one dimension.
Vertex A topological element corresponding to a point. It has zero dimension.
Shape A generic term covering all of the above.

Sadly I could not find the proper wiki page were this things are explained (or maybe some modifications deleted the relevant explanation.)

Hope it will be a little help.

Regards

Carlo D.

[heda]

with 99.9% probability, yes, you can do it without making a mesh first

if you attach a file, with the imported original part and your modification,
someone will come along and guide you.

btw, is this really a scripting question - modifications on unknown objects by means of scripting could be much trickier than just doing it by hand in the gui...

[chrisb]

Is Part Defeaturing what you are looking for?