Currently as far as I can tell it isn't possible to align an objects length (start and end point) along a spline only a single point that will try and rotate as it goes along the path.



in the example I have an upside down V shape that needs to have both end points follow the curve of the oval path but the align tool will only use one of these points so the other will come away from the path as it's mulitplied around. Is it possible that this function could be added at some point?

Cheers
Rob

In this case will be perfect to have possibily to remplace one object "instancied" by an another!
Here a cone by object "V" :)

Hi Rob - I think it is possible to get what you want there by converting your path to a polyline.

Check out this previous thread on how to do a tank tread type array, which is a similar problem:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1634.9

If you'd like to post a 3DM file with your particular curves in it, I can try to give you a demo with your exact situation.

- Michael

Maybe there is a little problem for see only points segments of the ellipse!
Maybe a edges + points type will be usefull !

Hi Pilou,

re: But point of trimming are mixed with control points of Ellipse.

Just turn control points off for the ellipse and they won't get in your way - there is a shortcut for this: push the Esc key, push it more than once if you have selected objects. The first press will deselect any selected objects and the second press will turn off control points.

Then window select everything including the ellipse, and then click the ellipse after that to deselect just it.

I've been thinking of adding in a "Points" entry for the Types section of the browser, but I am a little worried that it may be confused with control points though.

- Michael

Seems that don't works!

Hi Pilou, sorry I didn't understand - I thought you had some "Point" objects (created by Draw curve / More / Point). But it seems that you are talking about all control points?

If you would like to have some points you can use Draw curve / More / Point to place points at the end of each segment there, just make sure that Object Snap is enabled so you can get an "End" snap when you place the point.

But I don't really know why you want those points - is it to draw a polyline between them like that other message I showed previously did?

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.

- Michael

< 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!