< If so then you don't need to do that - just draw a polyline and use "End" object snap to snap each polyline point to the end of those segments, if you already have things split into parts you can use end snap for that rather than creating any points.

It's a very hard work when you have many points! (conceptual of course)
It's because I had make the trimming above (ellipse trimmed by vertical lines) ;)

It's not a polyline but some separated arc lines
But "end" and "start" points of these arcs can't be visible separated from the control points !

PS These points can be used for drawing something and must be separated from control points

So maybe a script show only Start End of curves can be useful?

> It's a very hard work when you have many
> points! (conceptual of course)
> It's because I had make the trimming above (ellipse
> trimmed by vertical lines) ;)

Hi Pilou, it is not so hard for your example - if you need help you can turn off all other snaps than End snap. You can do that by going to the menu that pops up when you move your mouse over the Object Snap button and right-click on "end" to enable only end.

Here is a demo with your particular case - total time is 12 seconds, is that really a very hard work?




If you do only want to get those points, I would suggest drawing in a point object initially rather than using vertical lines as the cutting objects as you have done here. See this previous example where I use points:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1634.9

If you want to end up with points there, then why do you use vertical lines? Why not just use points and then you will have points where it seems like you want them.

- Michael

Hi Pilou,

> So maybe a script show only Start End of curves can be useful?

Actually I have added something in for the next beta that will allow creating a point object at the start or end of a curve with a script.

But in the current Apr-12 beta that is not exposed to script yet though.

If you want points there though, I don't know why you decided to create vertical lines rather than points? Just create points to be the cutting objects and you will have what you want already.

- Michael

Yes I am agree for a little curve it's very easy to make that by hand ;) but for a big?

I have taken lines because I had in idea that some curves can be stacked above so can be trimmed in the same time

And no think to take points :)

And cool that in the next beta we can see only start / end of curves points

Hi Pilou,

> but for a big?

Well, for example it took me 12 seconds, so maybe with a curve 10 times as big it will take 120 seconds.

If you only need to do this occasionally, then that is not a big problem.


> And cool that in the next beta we can see only start / end of curves points

Oops, sorry I did not explain it clearly - it is not that you will only be able to see start/end control points, it is that you will be able to have a script that will create point objects at the start or end of a curve. That is a point object like Draw curve / More / Point, not control points.

Control points will still work the same as currently.

- Michael

< If you only need to do this occasionally, then that is not a big problem
yes
but if a script can do the same maybe that's better :)
Draw a line between an ordered succession of points

< you will be able to have a script that will create point objects at the start or end of a curve
yes : what append when 2 curves have a common start/ end vertex between them?
points created are part of each curves or "double points" become one point?

Hi Pilou,

> but if a script can do the same maybe that's better :)
> Draw a line between an ordered succession of points

If you have them saved to a text file in their ordered sequence, then I think that Petr's "Import Point file" plugin is able to do that:
http://kyticka.webzdarma.cz/3d/moi/#ImportPointFile


> points created are part of each curves or "double points" become one point?

You would get double points unless you wrote the script to detect this situation.


But again - if you just start out with a point object initially and replicate that around the curve rather than vertical lines, there is no need for creating any more points, they will be in place already.

So I'd recommend doing that, since it is both easier and works right now as well..

- Michael

I will try these Peter plugs (import/export) for test the little problem above ;)

Works fine! So for more 20 points that is very easy :)

No problem but...
Something curious in the Save point text help file it's written
< In the dialog box, type a name for the file including some extension like .txt, .csv, .xyz; e.g. outline.txt

but there only the normal export file window so works fine in 3Dm ;)

and for the import point text help file it's written nothing
but import file window is .txt, .csv, .xyz and hopefully *.*

Hi Pilou,

> Something curious in the Save point text help file it's written
> In the dialog box, type a name for the file including some extension
> like .txt, .csv, .xyz; e.g. outline.txt
> but there only the normal export file window so works fine in 3Dm ;)

Yes, that's not too unusual that with text files you will be allowed to type in many different extensions.

For example if you run notepad, you can enter any extension that you wish, including .3dm.

But it is not recommend that you do that, because a proper .3dm file is intended to be structured differently than a text file.

So doesn't seem like a problem!


> and for the import point text help file it's written nothing
> but import file window is .txt, .csv, .xyz and hopefully *.*

The extension is not so important - it is the contents of the file that is important, it should be a text file that contains numeric data, I think x,y,z data one point per line.

It is not unusual to have a .csv extension for a text file that contains "Comma Separated Values".

- Michael

in any case these 2 plugs are very useful for such little tricky things :)

It's a vicious little problem!
All the method works fine for a circle but not for an ellipse!
Because ellipse must be divided in equal arc elliptic of the size of the triangle!
And the Array / curve (ellipse-->polyline) seems don't make that!

And if you re scale the circle to an ellipse the triangle size is modify!

Hi Pilou, I guess you would need some specialized method to handle that...

- Michael

< some specialized method to handle that.
yes :)
length is good between the points (of the polyline) but the array curve don't manage the triangle over the polyline! ;)

So seems there is something wrong in the Array Curve function
Vertical works fine, obliques failed to follow the path along an ellipse
Ok I can make by hand but ...:)

Hi Pilou,

> So seems there is something wrong in the Array Curve function

Can you please post an example model? Or is it one of the previous files you posted?

- Michael

Thanks for the link to the tank track post Michael, but im baffled to see how it works! Surely the straight line distance around the curved bit will be shorter than the distance between the points on the straight bit as I think MOI (correctly) calculates the length of the curve not the shortest distance between points. I was wondering if it was possible for MOI to have an extra method that uses the straight line method for its calculation? Im thinking it would be useful in curved planar glass wall construction where the glass is usually made up of consistent sized glass modules, or possibly more complex shapes like the Swiss Re building in London - that was where the quick triangle experiment came from. Im thinking the actual swiss re shaped glazing pattern would be pretty hard to achieve with moi at the moment but a more basic purely horizontal curving should be possible. This way it would be easier to work with a single unit (structure and glazing) that could be then instanced (when the time comes) along the curve, rather than having each piece slightly different. Of course how these join propperly would need to be carefully managed but by and large it would be a big time saver.

Cheers

Hi Rob,

> Yes thanks for the link to the tank track post Michael, but im
> baffled to see how it works!

You know, I wasn't sure about that myself when I was looking over it again. I think that may have turned out well in that case just due to luck...

Because yeah you are right that array on curve goes by distance traveled along the curve, so polylines made in this way do not have equal length lines in them.

I guess by luck that previous one just did not happen to have much variation in the lengths just due to its regular curvature in the rounded areas.

So I suppose scratch that recommendation! :)


> I was wondering if it was possible for MOI to have an extra
> method that uses the straight line method for its calculation?

Generally something that is highly specialized like that would probably be some kind of plug-in rather than something that gets added to a fully general purpose function like the regular array curve...

The kind of thing you are talking about there just is not very general purpose - for example how would it behave when arraying a closed curve? What about when arraying a solid rather than a curve at all, etc...

When something only works on a very certain kind of geometry arrangement, that kind of brings out of the realm of the "general purpose" modeling toolset and more into a special focused kind of toolset.

With MoI, I'm still kind of in the phase of trying to make more progress in the "general purpose" toolset.

- Michael

A very simple example
Just one vertical + one Oblique = polyline A
The (1/4) ellipse = polyline (hand made after an array Curve Point / ellipse) with equal length
Array curve : that failed! (any position of the polyline A) it's the same for any forms except the verticals who are always good!