< I dont have snap points everywhere and im not on the grid.
The Custom Plan can't help? (Plan Auxiliaire)

"I dont have snap points everywhere and im not on the grid"

This was just an example case, It would be cool to draw lines from the center, very usefull.
No need mirror or duplicate etc...

You can also draw a line then Transform/ Scale 3D by the middle ="old "center" first click ;)
Seems the best simulation of what you want ;)

Yes, that's why I request a Line from Center point.
When you work fast, you loose a lot of time with small details like that :)
Its just a short way of doing what I already do manually.

Hi DesuDeus - you can use construction lines to get that kind of a line drawn more quickly.

If you haven't checked out construction lines yet, you're going to probably like them a lot. They enable creating a lot of precision placement things and by default they automatically go away after you have finished the command so there is no cleanup step like you have when creating a regular temporary line.

To make a construction line, when you go to pick a point instead of clicking the point, you press and keep the mouse button held down and drag it away. That creates a Construction line which is a kind of guideline that helps get you a variety of different snaps. When you release the mouse button the construction line will be formed from the start point to that released point.

Among the several things it helps with is to draw a line that is balanced around a particular midpoint.

Here's an example of how it works:




So notice there that when you create a construction line from the initial drag point to the place where you release the mouse, the reflected endpoint is also available as a snap, so that helps you to draw things that are halfway positioned around a midpoint.


One big benefit of this mechanism is that it works on any kind of point pick and not just as a special option for only the line command.

For example here I'm using it with Rectangle 3pts, to draw a square that is positioned with a midpoint of its edge in the same way:




> a 3 points line, wich can be transformed to an arc just by
> moving the center point)

You can also use construction lines to help you draw an arc as well - here I'm showing it using Arc 3 pts:




There are all kinds of other things you can do with construction lines too, like get a snap point midway between any 2 existing points, set up incremental snaps between 2 points (like 1/3 increments), capture a distance or direction between 2 points and relocate the line somewhere else to use it, do extensions, alignments, etc... Some more information on it is available here:

http://moi3d.com/1.0/docs/moi_command_reference10.htm#constructionlines

- Michael

Hi Grendel,

> I second this request, I am constantly making one line from
> center to a certain dimension, mirroring, then making a new
> line between the two and deleting the two original half lines
> because I don't want a center point on the resultant surface.

Check out the construction lines as shown above, it should speed up this process a lot.

Instead of drawing that first line that you describe in, you instead want to drag out a construction line first. To do that, while you are in the line command instead of clicking to place a point of the object being drawn, you instead hold the mouse button down and drag away.

That drags out a construction line - release the mouse on the end point, and now you will have snaps available exactly where you want to draw your line in. So then you pick those points to draw your line and then the construction line automatically goes away and you're done.

- Michael

Thanks for the effort Michael, but I was aware of that.
For my watches work I like to have a style locked colored in orange (I have a dark grid setup) that contain all the construction line, because I use them many times and sometimes for booleans.
Constructions lines are very cool for their purpose, but even with them I still miss a line from center point :)
Because a line from center point can be used for other things that just making construction lines.

Anyway thanks for all the time you take to write clear answers, have a good weekend.

Hi DesuDeus - I'm sorry I don't quite understand your last reply here...

By using a construction line, you can quickly create any line you want balanced around a midpoint.

Again, here is demo - here is a point and I will draw a line with its midpoint on that point (isn't this what you are asking to do?) all without exiting the line command:




> Because a line from center point can be used for other
> things that just making construction lines.

Sorry, I don't understand - as you see above, I'm creating a line from the midpoint, is that not the result that you are looking for?

That gives you the exact same result that a special "from midpoint" option in the line command would do - there is no difference in the result of what is drawn.

Again, I'm not sure if you are thinking that when I say "Construction line" if you think I'm talking about drawing in additional regular line objects which then need to be manually erased, which is not the case - a construction line is a special helper that you can create (while still inside of a drawing command!!) to set up additional snap points to help you in various things, including drawing a line that is balanced around a midpoint.

- Michael

Ohh okey I see now.
Well that's very cool :D
I just need to get used to it.
Maybe it would help people to have a separate icon in the UI.

Hi DesuDeus,

> I just need to get used to it.

Yeah, once you get used to it you'll probably find quite a lot of places where it can be useful. Pretty much any spot where you were creating temporary line objects is easier to do with this mechanism instead.

In a certain sense it allows you to quickly create a kind of temporary grid line adapted to your particular need of the moment. And then it goes away so you don't have to erase it.

There are a bunch of details on additional uses of construction lines here: (French translation by Pilou):
http://moi3d.com/1.0/docs/moi_command_reference10_French.htm#constructionlines


> Maybe it would help people to have a separate icon in the UI.

Unfortunately that would defeat one of the main functions of it, which is that it is so quickly available to be activated, since you can do it just by a quick "hold & drag" action with the mouse rather than needing to move all the way over to some other icon to activate it.

- Michael

Very clear explanations from Pilou, Its great sometimes to speak french :)
I was thinking of an icon that draw construction lines but permanent ones, like in sketchup.
But I dont know if it would draw locked curves, colored lines, or lines inside a custom group.

Hi DesuDeus, also you may want to check out that previous message I posted again, where I had several animations in it:

http://moi3d.com/forum/index.php?webtag=MOI&msg=2782.8

Those will probably make more sense now - every time in those animations where you see a dashed line being created, that is one of these special temporary construction lines.

You can see there how you can use it in any drawing command and not just while drawing a line, like there I create a square balanced on a midpoint, and draw an arc balanced around a midpoint, all without leaving those commands.

- Michael

Hi DesuDeus,

> I was thinking of an icon that draw construction lines but
> permanent ones, like in sketchup.

There is a plugin that you can use for that, it is in this discussion thread:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1029.1

- Michael

The on the fly construction lines are a powerful feature of MoI that I haven't seen anywhere else. Have you patented that system Michael?

However, I also like to use permanent construction lines and use that script A LOT. It is very good and I had hoped that this would make it permanently into MoI V2 as you really need both systems. Luckily, nothing Michael has done for V2 broke it :-)

Hi Tony,

> The on the fly construction lines are a powerful feature of
> MoI that I haven't seen anywhere else. Have you patented
> that system Michael?

No, it kind of tends to be a pain to get stuff patented, you have to hire a lawyer that's experienced in it and jump through several hoops.

Also the US Patent system is really a big mess when it comes to software patents, and it is frequently abused. I am happy to stay away from it as much as possible.

But yes, MoI's construction line system is unique as far as I know. There are several other systems that create guidelines on the fly, but every one that I have seen is similar to Ashlar-Vellum's original Drawing Assistant mechanism, where the lines radiate out from a single base point, rather than being more generally defined by 2 distinct points like MoI's construction lines are.

That's why the ones in MoI have so much additional functionality - stuff like the reflected endpoints as shown in the above screenshots, getting the midpoint between any 2 points, capturing a distance and using it elsewhere, etc... - much of that additional functionality is enabled because of having having 2 points defined for each guide line so that there is an actual distance associated with it and not just a location and direction only.

The other problem that tends to happen with the "Drawing Assistant" style lines is that they tend to trigger pretty easily and can quickly fill up your whole working area with snap zones, which is fine for simple mechanical drawings but really gets in the way if you are trying to do more subtle drawing with freeform curves and such. One other nice thing about MoI's system is that it stays out of your way until you want one.


> However, I also like to use permanent construction lines and
> use that script A LOT. It is very good and I had hoped that this
> would make it permanently into MoI V2 as you really need both
> systems.

There are still a few unresolved UI issues about making an "official" permanent construction line mechanism, like should you be able to select construction lines somehow so you could remove a particular one? At the moment there is not any infrastructure in place for that part.

Also, in addition to that custom command, you can also set up some keyboard shortcuts to keep the clines you have created in the current command:
http://kyticka.webzdarma.cz/3d/moi/#KeepCLine

- Michael

Hi, Michael,

I know that getting a patent is both expensive and time consuming so I'm not surprised that you aren't getting involved with that :-)

I know what you mean about the 2 point guides - this is what annoys me most about CorelDraw, only one point (in the version I'm using anyway). Back in the late 80''s, early 90's I use an app called Illustrator II from a company called Intercap. Is was a dedicated technical illustration system and ran on Apollo workstations. It had a brilliant guidelines system, including 2 point lines, circles, etc. I still miss it sometimes.

>> There are still a few unresolved UI issues about making an "official" permanent construction line mechanism,
>> like should you be able to select construction lines somehow so you could remove a particular one? At the
>> moment there is not any infrastructure in place for that part.

Er - I can do this now in the latest beta - click on construction line, shows up as a default style, press delete. Click and drag construction line to move it. Just need a built in command to add a permanent construction line. Or am I missing something?

What doesn't happen is that the line gets highlighted and there is no access to the right click menu to rotate etc. Would be nice to have that too.

Hi Tony,

> What doesn't happen is that the line gets highlighted
> and there is no access to the right click menu to rotate
> etc. Would be nice to have that too.

Yeah, it's some of the stuff relating to feedback on selection like the glow for mouseover highlights, and showing it in a selected state that does not currently work.

Also some other things like window select, ...

It will take some work to iron out all the details.

It's also probably not that great that when you make them stick that they can be moved so easily, probably it would be better if it behaved more like a background bitmap and stayed locked in place unless you went to a special command or mode to adjust them.

- Michael

>>It's also probably not that great that when you make them stick that they can be moved so easily,
>> probably it would be better if it behaved more like a background bitmap and stayed locked in place
>> unless you went to a special command or mode to adjust them.

I like this feature as it is - I would much rather have a lock guides feature than having to go into a special mode just to quickly adjust a guide that I didn't get in quite the right place the first time. Much nicer work flow. Making them like a background bitmap is the opposite of what I would expect. Should work just the same as for objects, imagine if all objects were locked just after you added them, then you had to enter a different mode to edit them :-)

Also, all the other apps I use that have guides work that way. Full adjustment unless guides are locked. Most of them just have a global lock all guides, doesn't work on individual ones.

Hi Tony,

> I would much rather have a lock guides feature

Well, that tends to be another problem, getting "feature creep" with getting a whole bunch of extra icons and special modes, etc...

That's kind of the path to UI complexity that I'm trying pretty hard to avoid overall with MoI in general.

That's why I would probably make the "lock/unlock" be kind of implicit within the command similar to background bitmaps. The construction lines would be locked (they are generally meant to be more of a snapping guide than to behave as regular objects) after you exited the special "cline" command, and if you wanted to adjust them you would go into that command which would allow you to adjust them.

Anyway, that just shows that it is a pretty complex area that needs a lot of thought before making it a final feature... That's why it did not really come together yet for version 2.

- Michael

Okay, I'm going to argue now :-)

>> Well, that tends to be another problem, getting "feature creep" with getting
>> a whole bunch of extra icons and special modes, etc...

But is that not what you are suggesting with ...

>> the special "cline" command,

and..

>> you would go into that command which would allow you to adjust them.

All I'm suggesting is to turn it around. One special command to lock all the guides. Manipulating guides works as now, but on persistent clines. Click, drag, right click get the wee menu. No extra icons required except for lock guides.


Just my tuppence worth ;-)