Joining Surfaces or Curves

This task shows how to join at least two surfaces or two curves.

The surfaces or curves to be joined must be adjacent.

1. Click Join  .

   The Join Definition dialog box appears.

2. Select the surfaces or curves to be joined.

3. You can edit the list of elements to be joined:

   by selecting elements in the geometry: Standard selection (no button clicked): when you click an unlisted element, it is added to the list  when you click a listed element, it is removed from the list Add Mode:  when you click an unlisted element, it is added to the list  when you click a listed element, it remains in the list Remove Mode:  when you click an unlisted element, the list is unchanged  when you click a listed element, it is removed from the list by selecting an element in the list then using the Clear Selection or Replace Selection contextual menu items.
   	If you double-click Add Mode or Remove Mode, the chosen mode is permanent, i.e. successively selecting elements will add/remove them.  However if you click only once, only the next selected element is added or removed. You only have to click the button again, or click another one, to deactivate the mode.

4. Right-click the elements from the list and choose Check Selection from the contextual menu.

   This lets you check whether any element to be joined presents any intersection (i.e. at least one common point) with other elements prior to creating the joined surface:

   The Checker dialog box is displayed, containing the list of domains (i.e. sets of connected cells) belonging to the selected elements from the Elements To Join list.

5. Click Preview.

   An Information message is issued when no intersection is found.

   When an element is self-intersecting, or when several elements intersect, a text is displayed on the geometry, where the intersection is detected.

6. Click Cancel to return to the Join Definition dialog box.

7. Right-click the elements from the list, choose the Propagate command, and choose one of the options to allow the selection. It allows the selection of elements of same dimension to be added to the Elements To Join list.

   The initial element to propagate cannot be a sub-element Forks stop the propagation Intersections are not detected

8. Click Preview in the Join Definition dialog box.

   The joined element is previewed, and its orientation displayed. Click the arrow to invert it if needed.
   	The joined element is oriented according to the first element in the list. If you change this element, the join's orientation is automatically set to match the orientation of the new topmost element in the list.

9. Check Check tangency to find out whether the elements to be joined are tangent. If they are not, and the option is checked, an error message is issued.

10. Check Check connexity to find out whether the elements to be joined are connex. If they are not, and the option is checked, an error message is issued indicating the number of connex domains in the resulting join.
    When clicking Apply, the free boundaries are highlighted, which help you detect where the joined element is not connex.

11. Check Check manifold to find out whether the resulting join is manifold.

    Check manifold is only available with curves. Checking it automatically enables Check connexity.

12. Check Simplify the result to allow the system to automatically reduce the number of elements (faces or edges) in the resulting join whenever possible.

13. Check Ignore erroneous elements to let the system ignore elements that would not allow the join to be created.

14. You can also set the tolerance at which two elements are considered as being only one using the Merging distance.

15. Check Angular Threshold to specify the angle value below which the elements are to be joined.
    If the angle value on the edge between two elements is greater than the Angular Threshold value, the elements are not joined. This is particularly useful to avoid joining overlapping elements.

16. Click the Sub-Elements To Remove tab to display the list of sub-elements in the join.

    These sub-elements are elements making up the elements selected to create the join, such as separate faces of a surface for example, that are to be removed from the join currently being created. You can edit the sub-elements list as described above for the list of elements to be joined.

17. Check Create join with sub-elements to create a second join, made of all the sub-elements displayed in the list, i.e. those that are not to be joined in the first join.

    This option is active only when creating the first join, not when editing it. It is not available when the joined surface belongs to an ordered geometrical set or a partbody created in an hybrid environment. A message is displayed to inform you of the creation of a second join.

18. Click OK to create the joined surface or curve.

    The surface or curve (identified as Join.xxx) is added to the specification tree.
    	If edges or the faces have an angular threshold higher than the predefined value, a text is displayed on the geometry indicating the error type. You can either deactivate the check box or increase the value of the angular threshold, or remove all the elements or sub-elements that are in error.
    	Sometimes elements are so close that it is not easy to see if they present a gap or not, even though they are joined. Check the Surfaces' Boundaries option in Tools > Options > General > Display > Visualization.