Mesh Scripting/cs: Difference between revisions
(Updating to match new version of source page) |
(Updating to match new version of source page) |
||
Line 7: | Line 7: | ||
{{TOCright}} |
{{TOCright}} |
||
== |
==Introduction== |
||
First of all you have to import the Mesh module: |
First of all you have to import the Mesh module: |
||
Line 18: | Line 18: | ||
of the FreeCAD C++ Mesh-Kernel. |
of the FreeCAD C++ Mesh-Kernel. |
||
== |
==Creation and Loading== |
||
To create an empty mesh object just use the standard constructor: |
To create an empty mesh object just use the standard constructor: |
||
Line 38: | Line 38: | ||
planarMesh = [ |
planarMesh = [ |
||
# triangle 1 |
# triangle 1 |
||
[-0.5000,-0.5000,0.0000],[0.5000,0.5000,0.0000],[-0.5000,0.5000,0.0000], |
[-0.5000, -0.5000, 0.0000], [0.5000, 0.5000, 0.0000], [-0.5000, 0.5000, 0.0000], |
||
#triangle 2 |
#triangle 2 |
||
[-0.5000,-0.5000,0.0000],[0.5000,-0.5000,0.0000],[0.5000,0.5000,0.0000], |
[-0.5000, -0.5000, 0.0000], [0.5000, -0.5000, 0.0000], [0.5000, 0.5000, 0.0000], |
||
] |
] |
||
planarMeshObject = Mesh.Mesh(planarMesh) |
planarMeshObject = Mesh.Mesh(planarMesh) |
||
Line 46: | Line 46: | ||
}} |
}} |
||
The Mesh-Kernel takes care about creating a |
The Mesh-Kernel takes care about creating a topologically correct data structure by sorting |
||
coincident points and edges together. |
coincident points and edges together. |
||
Later on you will see how you can test and examine mesh data. |
Later on you will see how you can test and examine mesh data. |
||
[[#top|top]] |
|||
⚫ | |||
⚫ | |||
⚫ | |||
⚫ | |||
{{Code|code= |
{{Code|code= |
||
Line 60: | Line 62: | ||
This script provides methods to define simple rotation bodies like spheres, ellipsoids, cylinders, toroids and cones. And it also has a method to create a simple cube. |
This script provides methods to define simple rotation bodies like spheres, ellipsoids, cylinders, toroids and cones. And it also has a method to create a simple cube. |
||
A toroid, for instance, can be created as follows: |
|||
{{Code|code= |
{{Code|code= |
||
Line 67: | Line 69: | ||
}} |
}} |
||
The first two parameters define the |
The first two parameters define the radii of the toroid and the third parameter is a sub-sampling factor for how many triangles are created. The higher this value the smoother and the lower the coarser the body is. |
||
The Mesh class provides a set of boolean functions that can be used for modeling purposes. It provides union, intersection and difference of two mesh objects. |
The Mesh class provides a set of boolean functions that can be used for modeling purposes. It provides union, intersection and difference of two mesh objects. |
||
Line 86: | Line 88: | ||
{{Code|code= |
{{Code|code= |
||
import Mesh, BuildRegularGeoms |
import Mesh, BuildRegularGeoms |
||
sphere = Mesh.Mesh( |
sphere = Mesh.Mesh(BuildRegularGeoms.Sphere(5.0, 50)) |
||
cylinder = Mesh.Mesh( |
cylinder = Mesh.Mesh(BuildRegularGeoms.Cylinder(2.0, 10.0, True, 1.0, 50)) |
||
diff = sphere |
diff = sphere |
||
diff = diff.difference(cylinder) |
diff = diff.difference(cylinder) |
||
d = FreeCAD.newDocument() |
d = FreeCAD.newDocument() |
||
d.addObject("Mesh::Feature","Diff_Sphere_Cylinder").Mesh=diff |
d.addObject("Mesh::Feature", "Diff_Sphere_Cylinder").Mesh = diff |
||
d.recompute() |
d.recompute() |
||
}} |
}} |
||
[[#top|top]] |
|||
== Examining and Testing == |
|||
⚫ | |||
== Write your own Algorithms == |
|||
⚫ | |||
You can even write the mesh to a python module: |
You can even write the mesh to a python module: |
||
Line 108: | Line 108: | ||
}} |
}} |
||
[[#top|top]] |
|||
== Gui related stuff == |
|||
== |
==Notes== |
||
An extensive (though hard to use) source of Mesh related scripting are the unit test scripts of the Mesh-Module. |
An extensive (though hard to use) source of Mesh related scripting are the unit test scripts of the Mesh-Module. |
||
Line 117: | Line 117: | ||
See also [[Mesh_API|Mesh API]] |
See also [[Mesh_API|Mesh API]] |
||
[[#top|top]] |
|||
<div class="mw-translate-fuzzy"> |
<div class="mw-translate-fuzzy"> |
Revision as of 08:48, 28 May 2020
Introduction
First of all you have to import the Mesh module:
import Mesh
After that you have access to the Mesh module and the Mesh class which facilitate the functions of the FreeCAD C++ Mesh-Kernel.
Creation and Loading
To create an empty mesh object just use the standard constructor:
mesh = Mesh.Mesh()
You can also create an object from a file
mesh = Mesh.Mesh('D:/temp/Something.stl')
(A list of compatible filetypes can be found under 'Meshes' here.)
Or create it out of a set of triangles described by their corner points:
planarMesh = [
# triangle 1
[-0.5000, -0.5000, 0.0000], [0.5000, 0.5000, 0.0000], [-0.5000, 0.5000, 0.0000],
#triangle 2
[-0.5000, -0.5000, 0.0000], [0.5000, -0.5000, 0.0000], [0.5000, 0.5000, 0.0000],
]
planarMeshObject = Mesh.Mesh(planarMesh)
Mesh.show(planarMeshObject)
The Mesh-Kernel takes care about creating a topologically correct data structure by sorting coincident points and edges together.
Later on you will see how you can test and examine mesh data.
Modeling
To create regular geometries you can use the Python script BuildRegularGeoms.py.
import BuildRegularGeoms
This script provides methods to define simple rotation bodies like spheres, ellipsoids, cylinders, toroids and cones. And it also has a method to create a simple cube. A toroid, for instance, can be created as follows:
t = BuildRegularGeoms.Toroid(8.0, 2.0, 50) # list with several thousands triangles
m = Mesh.Mesh(t)
The first two parameters define the radii of the toroid and the third parameter is a sub-sampling factor for how many triangles are created. The higher this value the smoother and the lower the coarser the body is. The Mesh class provides a set of boolean functions that can be used for modeling purposes. It provides union, intersection and difference of two mesh objects.
m1, m2 # are the input mesh objects
m3 = Mesh.Mesh(m1) # create a copy of m1
m3.unite(m2) # union of m1 and m2, the result is stored in m3
m4 = Mesh.Mesh(m1)
m4.intersect(m2) # intersection of m1 and m2
m5 = Mesh.Mesh(m1)
m5.difference(m2) # the difference of m1 and m2
m6 = Mesh.Mesh(m2)
m6.difference(m1) # the difference of m2 and m1, usually the result is different to m5
Finally, a full example that computes the intersection between a sphere and a cylinder that intersects the sphere.
import Mesh, BuildRegularGeoms
sphere = Mesh.Mesh(BuildRegularGeoms.Sphere(5.0, 50))
cylinder = Mesh.Mesh(BuildRegularGeoms.Cylinder(2.0, 10.0, True, 1.0, 50))
diff = sphere
diff = diff.difference(cylinder)
d = FreeCAD.newDocument()
d.addObject("Mesh::Feature", "Diff_Sphere_Cylinder").Mesh = diff
d.recompute()
Exporting
You can even write the mesh to a python module:
m.write("D:/Develop/Projekte/FreeCAD/FreeCAD_0.7/Mod/Mesh/SavedMesh.py")
import SavedMesh
m2 = Mesh.Mesh(SavedMesh.faces)
Notes
An extensive (though hard to use) source of Mesh related scripting are the unit test scripts of the Mesh-Module. In this unit tests literally all methods are called and all properties/attributes are tweaked. So if you are bold enough, take a look at the Unit Test module.
See also Mesh API
- Miscellaneous: Import mesh, Export mesh, Create mesh from shape, Regular solid, Unwrap Mesh, Unwrap Face
- Modifying: Harmonize normals, Flip normals, Fill holes, Close hole, Add triangle, Remove components, Remove components by hand, Smooth, Refinement, Decimation, Scale
- Boolean: Union, Intersection, Difference
- Cutting: Cut mesh, Trim mesh, Trim mesh with a plane, Create section from mesh and plane, Cross-sections
- Components and segments: Merge, Split by components, Create mesh segments, Create mesh segments from best-fit surfaces
- FreeCAD scripting: Python, Introduction to Python, Python scripting tutorial, FreeCAD Scripting Basics
- Modules: Builtin modules, Units, Quantity
- Workbenches: Workbench creation, Gui Commands, Commands, Installing more workbenches
- Meshes and Parts: Mesh Scripting, Topological data scripting, Mesh to Part, PythonOCC
- Parametric objects: Scripted objects, Viewproviders (Custom icon in tree view)
- Scenegraph: Coin (Inventor) scenegraph, Pivy
- Graphical interface: Interface creation, Interface creation completely in Python (1, 2, 3, 4, 5), PySide, PySide examples beginner, intermediate, advanced
- Macros: Macros, How to install macros
- Embedding: Embedding FreeCAD, Embedding FreeCADGui
- Other: Expressions, Code snippets, Line drawing function, FreeCAD vector math library (deprecated)
- Hubs: User hub, Power users hub, Developer hub