Hi Rob,

> OK but surely the trim command just uses a single line to divide objects

Actually no - you are not restricted to only use a line as the cutting object, you can use any intersection between solids, surfaces, or curves, including when things swoop around with 3D shapes instead of only planar shapes.

Here's a quick example of 2 non-planar surfaces:



Now using the second one as a cutting object to trim the first:




When things are all swooping around in 3D rather than all on a plane, there may not be something that equates with a "side" as you may have in a 2D plane type situation.


Also if it took everything off to one side in 2D situations, it would then make some things not work, like for example here I had a goal of trimming off only one part that intersected with the line, not everything:







If it only worked by throwing away everything to one side, that result above would not be possible without extra steps to draw a shorter cutting line.

By selecting which fragments are to be removed (or kept if you have switched to "keep" mode), it lets you have this kind of flexibility.


In the future I may be able to add something like you are talking about for the 2D curve case, where if you clicked on an empty space rather than on a fragment, it would see if it could determine a side and do a kind of batch select. I've thought about that some before. But that's a pretty customized selection function that is not really similar to other current selection functions, so it will take some extra work to make that happen, that's why it is not in there yet.

Really the window select should make what you need there happen pretty easily though - does it not work well with something you are trying to do? Maybe if you could post the 3DM file that would help me to understand what you are running into, or maybe I could then demonstrate how to make it work quickly with your specific example.


> is there a way to use either the delete key or enter key for this command?

There is no way to do it currently, it will require making the Trim command have a kind of special override for that key so that it would not trigger the usual shortcut for the Delete command. I'll see what is involved in setting that up.


> although I can get myselft confused with how many times
> i've pressed it during an opperation and where i am in an
> opperation, often clicking not enough or too many times
> and repeating the command.

Try to watch what the prompt text says, in this area:



That's meant to be a kind of guide for what is currently going on, like what action MoI is currently expecting for you to do.

It will say things like "Pick a Point", "select objects to do something to", etc...

If you look up there it can help you to know what is going on right at that stage.

- Michael

Hi Rob, here is another example where the "side" is not so clearly defined.

Here I am trimming the zig-zag with the line:



Which side of the line do you consider this fragment to be on:



When things don't fully divide the entire plane up into different regions, there may not be a fully defined "side" really in there...

- Michael

Thanks michael once again for your in depth reply. On your last post I would say there are three fragments. Perhaps rather than just having two sides as it were moi could temporarily auto group objects that have been split or partially split by the cutting object so here there would be three groups availiable for selection rather than a series of individual lines. This could be purely as an additional option on top of the current work flow. I remember working on a dummy test file and being frustrated by having to manually select the trimmed lines/objects - probably some sort of standing seam roof. Im often in two minds whether to use trim or bool in some situations as they often have the same outcome - which is no bad thing I guess.

Cheers

Hi Rob,

> I remember working on a dummy test file and being
> frustrated by having to manually select the trimmed
> lines/objects - probably some sort of standing seam roof.

Do you happen to still have the file around? If so, can you please post it?

That would let me demonstrate on that particular example how to use a strategic window select to grab a batch of things, instead of manually clicking on each one.


> Im often in two minds whether to use trim or bool in some
> situations as they often have the same outcome - which is no
> bad thing I guess.

Yeah for curves there are many situations where they work the same. But the difference is much more pronounced when you use them with solids - Trim will cut only the "skin" of a solid, while booleans will work on the volumes of a solid.

- Michael

Hi Rob - also I've got it set up for the next v2 beta so you can hit the Delete key in Trim to finish after picking pieces to discard, it works the same as Enter, clicking "Done", or right-clicking.

- Michael

sweet thanks for that michael im sure it will save me a lot of cursing! I think with the right clicking I do look at the top right info box but sometimes its too late or im a bit over eager on the buttons, also I'f im using that technique I like to look at the area im working on rather than the top right of the screen. Think for this command i'll just stick to my old fashioned delete key.

Thanks again.