From:  Michael Gibson
3806.2 In reply to 3806.1 
Hi Ed, so the difficulty with the AutoCAD Trim process is that it has an inconsistent workflow with how many people expect for modification commands to work in general.

What I mean is that usually people expect to select the object to be modified before running the command. That kind of noun-verb sequence is just the most common way that everything tends to work on the computer in general. For example if you want to delete a file in Windows Explorer, you don't first activate the Delete command and then go pick which file you want to delete, instead you first select the file you want to delete and then trigger the delete action.

AutoCAD's Trim workflow does it in the reverse way - instead of picking the object that will be modified first, it picks the cutting objects first, then the object that you want to modify is selected in a step after that.

That's a bad design from a consistency standpoint - having some operations select the objects to be modified in reverse order from other operations can tend to make things more difficult for beginners to figure out, even if there is possibly some kind of efficiency to be gained from it.

MoI's Trim works by selecting the objects to be modified first, and then cutting objects after that, and selecting the objects to be modified initially helps to keep Trim working in a similar pattern to other modification commands rather than having some completely custom and different workflow to it. That kind of consistency is one of the things that help make MoI easier to learn how to use...

Also one other thing with MoI's Trim command workflow is that it allows for a splitting operation where you can decide to cut things up and leave all the pieces behind by pushing Done (or right-clicking or typing Enter) at the prompt for selecting which pieces to discard. That's not possible with AutoCAD's Trim command.

So anyway, those are the reasons why MoI's Trim command is not set up like AutoCAD's.

But I think in the future I'll probably make some additional set of "quick drafting" type plug-ins that you'll be able to optionally install which will give some tools that do work like AutoCAD. For optional plugin extension things like that I won't be as concerned about inconsistent workflows.

- Michael