How to fix Intersecting, Self Intersecting, or Irregular Faces. These can be found visually or by using the Object Doctor, (see Tip #91). This is especially useful when exporting solid objects for 3D printing.
If the intersections are easy to identify then just move the points/segments/faces using any method:
Method A: Select Pick tool, choose a Topological Level, click on a point/segment/face, then use Move tool.
Method B: Select Move tool, hold down Cmd key (Mac) or Ctrl (Win), then click and drag a point/segment/face, (see Tip #23).
Method C: Select Transform tool, hold down Cmd key (Mac) or Ctrl (Win), click on a point/segment/face, then move the transform widget controls to adjust the entity, (see Tip #1).
If the intersections are more complex then delete the faces in the problem area, recreate a valid surface, then Stitch it back into the object to create a valid solid again as follows:
To delete faces select Delete tool, hold down Cmd key (Mac) or Ctrl (Win), then click on faces to delete.
One method to recreate a surface is to select the Vector Line tool with the 2D Surface option and snap to the boundary points, (optional: turn Show Points ON in Display Options). If the boundary line you created is planar then a face is automatically filled inside the boundary. If the boundary line is non-planar then no faces are created. If this happens use the Triangulate tool with the Center option to fill the non-planar boundary you just created with a surface.
Another method to recreate a surface is to select the Pick tool, select the Segment Sequence icon in Tool Options, then click on one edge and the entire boundary should highlight. If so, then select 2D Derive Segment tool, choose Join Selected Segments in Tool Options, then click a blank area and a boundary line is created. Again, if the boundary line created is non planar then use the Triangulate tool to fill the boundary with a surface as discussed previously.
A third method is to use the Cap tool, (see Tip # 59). Note, this tool always creates a “smooth” surface. If needed you can convert this smooth surface to facetted, (see Tip #93).
When you are ready to stitch your new surface back onto your object select the Stitch tool, click on the object, then your new surface, and they should stitch together resulting in a valid solid. Check to verify the resulting object is solid, (see Tip #92)