True darts

[Former user]

Hi Roman, I'd like to true my dart legs but unable to find a way to do it. I would need to rotate objects to true them. Any support here?I could export via svg and do it in inkscape but was wondering if it can be automated. Thanks, Preethi.

[Roman Telezhynskyi]

Can you explain me more detail? I am not sure i understood your request. Do you speak about passmarks?

[Former user]

Hi Roman, I do not know what is passmarks. Basically after I draw the darts, I want to make sure they are the same length and also they will be on same shoulder slant for example. I've created an svg file in inkscape showing in layers the steps I need to do manually before I reeach to be final dart legs. On the svg there are several layers, pls start from the most below layer traversing one by one to see the steps. Thanks, Preethi.

[Roman Telezhynskyi]

I would need to rotate objects to true them. Any support here? I could export via svg and do it in inkscape but was wondering if it can be automated. I think, yes. For this task i propose make new tool that will create new point. This new point will be correct position for dart.

[Former user]

Hi Roman, I see you have replicated the steps on the same page. Any way to automate this in val? Thanks Preethi

[Roman Telezhynskyi]

Any way to automate this in val?

Yes, i think we could automate this. But i don't know how quick i could make this feature. Too many more prioritized tasks.

[Former user]

Ok No probs. Thanks

[Former user]

Actually it is not to hard to calculate the points d1_new and d2_new. Unfortunately at the moment its very tedious to enter such formulas in valentina. As I'm not familiar with pattern making, I have a question:

Whats the usual workflow? Do you choose d1,d2 and d3 ( with d1 and d2 on a line with p1, p2 ) or do you choose d3 and the angle theta? Or d1, d2 and the lenghts d1-d3, d1-d3 ?

[Roman Telezhynskyi]

Whats the usual workflow? Do you choose d1,d2 and d3 ( with d1 and d2 on a line with p1, p2 ) or do you choose d3 and the angle theta?

I plan make it like this: choose p1, d1, d2, d3, p2. Also two new names for d1_new and d2_new. Actually it is very easy tool. But right now allow many code strings. And i begun little refactoring in code base. Want make it more modular.

As I'm not familiar with pattern making, I have a question

Do you want make it yourself?

[Roman Telezhynskyi]

In this case i prefer don't use formulas.

[Former user]

I don't want to implement it using just plain formulas. I just wanted to point out that it is possible. So there is no need to this fore and back rotating.

I agree, a dedicated tool is much more appreciate. I just wonder why you preethiraj even mention the angle theta. Maybe that's the way to make darts, but apparently its not. So I would have proposed the same as you did. Choose points P1,P2, D1, D2, D3 and get the new points as a result.

Moreover, a little off-topic here, but still related. I think we should have (both) intersecting angles of two lines as a measurement available. Now we have only some kind of absolute angle (wrt to coordinated axis) of a line.. It is cumbersome to write sth like (angle_of_line_1 - angle_of_line_2).

[Roman Telezhynskyi]

I think we should have (both) intersecting angles of two lines as a measurement available.

I understand you, but we already have a lot variables. And intersecting angles of two lines has much more results than one (four possible angles).

And i am not sure this kind of variable we use very often.

[Former user]

Of course 1=2 and 3=4, so there are basically just two. Is there any kind of limit on such "derived measurements"? I think we should be generous in providing variables.

Also I guess, the notion of "angles between lines" is more useful than current notion of "angle of a line". I don't see a use for the latter, but may be there is?

[Roman Telezhynskyi]

Of course 1=2 and 3=4, so there are basically just two.

Yes, you are right, only two.

Is there any kind of limit on such "derived measurements"?

I don't see any, except space in dialog. And user that will confuzed so big number of different variables.

I think we should be generous in providing variables.

May be, may be not. For me enough use sth like (angle_of_line_1 - angle_of_line_2).

Also I guess, the notion of "angles between lines" is more useful than current notion of "angle of a line". I don't see a use for the latter, but may be there is?

In pattern making all depend on your approaches in making patterns. I personally never meet case where need "angles between lines", but hundred times cases where need "angle of a line".

I don't have plans to add variable "angles between lines", but if some one want provide a patch here examples: c63bf4b and 538edde. See part about adding new variables.

[Former user]

In pattern making all depend on your approaches in making patterns. I personally never meet case where need "angles between lines", but hundred times cases where need "angle of a line".

Ok. I cant judge as I am not familiar with pattern making, so I believe you.

Maybe we should provide something like custom variables, kind of user defined shortcuts for functions of built variables.

[Roman Telezhynskyi]

Maybe we should provide something like custom variables, kind of user defined shortcuts for functions of built variables.

Yes, it will be possible in New Measurement Standard (#181). Also see section about Increments.

[Former user]

Hi Roman, Stephan, you could ignore the angles and only use the lines. Basically line d2-d3 should coincide with line d3-d1. This essentially is making the angle as 0 or closing the angle. When an object is rotated to coincide the lines or close the angle it should be rotated on the axis of point d3. Here is video - http://www.ralphpink.com/pattern-cutting-basic-bodice-block/ - Please watch from 1:28:50 to 1:31:50.

This type of rotation on an axis will also help in dart manipulation. If we want to move the dart from shoulder to say armhole then we can use the same logic except we wouldnt want to open it back again.

[Former user]

Ok, as Roman already said, the angle is not important - you start by segmenting the line with D1,D2, and then choose D3..

For me the potential tool does no rotation at all, it just gives you the points D1* and D2*. I think about something like this:

• From the segments P1-D1, D3-P1 and D3-D1 you can calculate phi_1. Similarly phi_2.
• From phi_1+phi_2 , D3-P1 and D3-P2, you can calculate the length of the green line.
• From this you can get beta_1 and beta_2
• And finally the length of the red line, hence the points D1* and D2*

The requirement is, to choose beta1 and beta2 in such a way that both red lines have the same length and alpha1 and alpha2 sum up to 180°. (sorry for the crappy image)

Do you see any need for doing explicit rotations as in the video (thx for the link)? Because I don't get what you mean by

If we want to move the dart from shoulder to say armhole then we can use the same logic except we wouldnt want to open it back again.

[Roman Telezhynskyi]

Stephan, why do you ask about this tool? Do you want to try make it?

[Roman Telezhynskyi]

Ok, as Roman already said, the angle is not important - you start by segmenting the line with D1,D2, and then choose D3..

When i said "the angle is not important" i meant we can calculate it from points. Don't need request from user the angle value.

For me the potential tool does no rotation at all, it just gives you the points D1 and D2.

It is because you found another approach to find points. If i would do this tool i will use rotation around point (D3).

Do you see any need for doing explicit rotations as in the video (thx for the link)? Because I don't get what you mean by

Here rotation is hidden, but in some cases pattern maker want close dart in one place and open in another. There will be rotation piece of pattern.

[Former user]

Well just general interest, i am not yet enough into the codebase, to realize sth useful.

[Roman Telezhynskyi]

Well just general interest, i am not yet enough into the codebase, to realize sth useful.

Good, because i begun making this tool.

[Former user]

Hi Stephan

"If we want to move the dart from shoulder to say armhole then we can use the same logic except we wouldnt want to open it back again." By this I meant dart manipulation - Here is a video - https://www.youtube.com/watch?v=y1M3aW_jNP8. The rotation would enable to open up another area for dart by closing one. Currently I'm having to take the basic block and take it to inkscape to do any manipulation.

[Roman Telezhynskyi]

Here also my example from my mom's old book:

[Former user]

Ah, I see rotation is essential. Good we have talked about..

[Former user]

Hi Roman, Is the feature available for use? Thanks,Preethi

[Roman Telezhynskyi]

Hi Roman, Is the feature available for use? Thanks,Preethi

Yes, but need wait new release 0.4.0 or next test build. I think next test build will be after several days.

[NataliaTroitskaya]

Hi there! Just starting to use Valentina and so far really like the program. But now having the same concern regarding the darts manipulation. I know that you've listed this problem as solved, but I would love to have a little explanation on how to rotate the piece and manipulate with darts?) Thanks in advance!

[Roman Telezhynskyi]

http://forum.valentina-project.org/t/true-darts-tools/858/2?u=dismine

[NataliaTroitskaya]

Thanks a lot! But I was asking more about the manipulation of that dart (as on the example of your mum's old book above), any rotation that can be used to close the existing dart and open a new one?