> Hi Dave, so what kind of ghost objects are you seeing with the line, is it an extra point object?

I never use 'update' calls in my code. Previously, when I was still seeing the 'ghost' objects, the only factory call I was using was 'calculate'. Now, in addition to 'calculate', I also call 'cancel' after the call to 'calculate', which seems to eliminate the 'ghost' objects when creating things like lines.

What I mean by a 'ghost' object is a copy of a created object (like a line) that was never explicitly added to the geometry database (i.e. because only 'calculate' was used to create it), but which nevertheless shows up in the viewport.

The situation is usually as follows:

- Run a script that creates a line (using 'calculate'), but which never gets added to the geometry database.
- The viewport looks OK at this point (i.e. the created line is not visible, since it was not added to the geometry database).
- Now, using the UI (not a script), start an interactive operation, like creating another line. Click with the mouse to set the line's start point.
- At this point, the original line (created by the script in step 1), appears in all viewports.
- Complete the drawing of the interactive line by clicking to set the end point.
- At this point, the interactively created line is visible, and the 'ghost' line from step 1 disappears, never to be seen again.

Another attribute of 'ghost' geometry is that it can never be selected by clicking (no pre-selection highlight, no selection highlight), but can be selected by box dragging (normal pre-selection highlight and final selection highlight). However, once selected, the object cannot be moved, deleted, etc., although it does eventually go away, as described in the preceding series of steps. You would see this behavior immediately after running the script, when attempting to click or drag select on the empty space in the viewport where the created line should be.

So it looks like there are some circumstances where 'calculate' does put created geometry into a state where it may be displayed for a short while (usually during the extent of the next command). As I mentioned, placing a 'cancel' call after the call to 'calculate' does seem to clear up the problem (in most cases, although 'reset' seems to do a better job when using the 'trim' factory, as I mentioned before).

At this point, with the 'reset' (for 'trim') and 'cancel' (for everything else) calls in place, I have not seen any 'ghost' geometry at all. The only anomalous behavior I am seeing at this point is that when running a fairly complex script that creates lots of intermediate geometry, using a mixture of different factory operations, MoI sometimes ends up in a state that seems like it is waiting for a command to end. That is, the viewports all look fine, and may contain correctly selected objects (created by the script), but I cannot deselect existing objects or select new ones. Pressing 'enter' or 'esc' seems to exit whatever state is in in, and things are back to normal after that. I'm still investigating this, and it may be due to some other error in my script...