Cut a face in the middle
Cut a face in the middlePosted by maxpenner at January 27. 2013
I would like to split a face exactly in the middle within the Salome geometry module. I use Salome 6.6.0. When I select a face, I can see a cross through the face which shows me, that the face is selected. I would like to split the face exactly through these lines.
Is this possible? Maybe with python scripting?
I propose this method in the GUI (no script needed):
A) For non-straight iso-curves:
- 1- New Entity -> Basic -> Point, then last icon at the top right of the dialogue box (point on a surface).
- 2- Create three points along the U-curve or the V-curve depending on what curve you want to use. Then close the dialogue box.
- 3- New Entity -> Basic -> Plane, then second icon (plane from three points).
- 4- Create a plane from the three points you created on your iso-curve.
- 5- Operations -> Partition.
- 6- You can then partition your face with your plane.
B) For straight iso-curves:
- 1- New Entity -> Basic -> Point, then last icon also.
- 2- Create two points at the extremities of the U-curve or the V-curve, with parameters 0 and 1 (no matter if the vertex go outside the surface). Close the dialogue box.
- 3- New Entity -> Basic -> Line.
- 4- Create a line linking the two points created on your iso-curve.
- 5- Operations -> Partition.
- 6- Partition your face with your line.
Of course, this could be easily scriptable
After reflexion, I admit that this method is not suitable for non-planar iso-curves (that can happen when the face was created from a filling, for example). In this case, you should rebuild the iso-curve with a spline. You can do it by creating not only three points but more than that on your surface, and from a parameter of 0 to 1. For example: 0 , 0.1 , 0.2 , ... , 0.9 , 1.
Then, to rebuilt the iso-curve: New Entity -> Basic -> Curve, then last icon.
You can then partition your face with it. If the partition fails, use Repair -> Limit Tolerance on your iso-curve or/and on your face to increase the tolerance during the partition. If it is not sufficient, you can extrude your iso-curve in an approximative face normal direction (New Entity -> Generation -> Extrusion, then third icon and checking the "Both Directions" box), and use the extrusion as a tool for your partition.
Re: Cut a face in the middlePosted by maxpenner at January 28. 2013
thank you for your answer. Now I use the following solution:
1. Create three points via 'New Entity -> Basic -> Point' and select the last item 'construct with U and V parameters'.
I take the following parameters (By trying, I find which parameter U or V I must change):
- U1/V1 = 0.5/0.5
- U2/V2 = 0.5/0
- U2/V2 = 0.5/1
2. If the three points are not colinear, I can create a new plane with them.
3. I create a partition with the face and the plane
4. I extrude the partition into faces and get two faces.
If I have a lot of such faces, I write a python script which does calculate the split faces.