Adaptive Family with parallel cables

[Anonymous]

Hi,

I've been trying to create an adaptive family tha has parallel lines controlled by the same adaptibe point, but the problem is that when i put the family with Dynamo, it is unable to create form. After multiple tries it seems that de points that are hosted to adaptive points change positions (the points hosted to other points that are hosted on my reference line don't have this problem) , and maybe there's my problem. Doe's anyone  knows how to fix this and make the family work properly?

Here is an example of hoy i want my family to look like.

[RDAOU]

@Anonymous 

Hosting directly to the Adaptive placement point in your case is not ideal. The orientation of placement points depends on their defined parameter "Orients to" and/or the orientation of their host...With the points hosted on the reference lines always follow the orientation of their host the reference line ie: the path of the rail

Hence the inconsistency and mix between hosting to points residing on the path and to the placement point makes the form also inconsistent...I would stick to the points hosted to the reference lines. See below video:

PS:

1. the rails in the video should remain parallel until you intentionally stretch/force them to self intersect. This is due to the lack of hosted points to constrain the spline
2. Hosting an adaptive profile on a divided curve (parameterize the number of nodes to smoothen the spline would give you better results

[ToanDN]

Wouldn't using 3 profiles sweeping along the same one path create 3 parallel cables?

[RDAOU]

Have you ever seen those puppeteers with several puppets tied to rails behind and in front of them to mimic their own movement? They might not be engineers but they definitely do know more about Kinematics and biomechanics than many

[Anonymous]

Thank you for your answers, they might solve part of my problem. The other problem is: im trying to make a family for post tension cables, so i need the cables close to each other in the middle of spline, and i need them separated in the first and last 1,9 meters. Here's an image of the family that doesen't work.

Hoy could i do this? Is it possible to split my reference line? So i can host my points on it with the parameter based in a point after the cables are together.

I would also like to know if it is possible to remove these projection black lines.

Thank you again for your answers 🙂

[ToanDN]

Is this not what you are talking about?

[RDAOU · Accepted solution]

@Anonymous 

Watch the video again and notice the points hosting the left and the right path. I have associated all with the same parameter on each side and its inverse on the other... you can reconfigure them as in below Image. Usually if you are placing this using dynamo, the graph should do the distribution for you where up to a certain point they run parallel then diverge at the ends. Se GIF below

If you are using dynamo for placement, you should also take into consideration the placement method. Will you be using 1 curve and the 3 rails as a single element and control the offset to define where they run parallel and where they diverge? or would it be easier to create 3 curves directly in dynamo and  placing 1 mono rail to each curve...both ways it is possible

For the black line...you have used model lines...Select them and on the properties palette check the box "Is Reference Line"

[Anonymous]

This is an ok solution when you have small cables, but when it comes to a bigger scale, doesn't work that well. an exemple: Let's suppose that in my family, my cable has 50m long. if i have that my cables join together at 1,9m (it will be always be on 1.9, not depending on the total cable length) on segment length and my next point is at 2.5m (parameter of 0,05) when i have a situation in my project that my cable has only 20 meters, this point with 0,05 parameter will be at 1 meter at segment length, behind my 1,9 meter point, so the family is now unable to create form.

[RDAOU · Accepted solution]

The dimension and proportions you have in the last two images do not appear to be realistic...what are the diameters of those cables?

Again, refer to the initial reply...a divided path with the adequate numer of nodes will give you better results at long distances. On similar projects I have used a somewhat similar family also for post tenssioned bridge with 35m spans . Your dynamo need to be able to control the points otherwise the spline wont behave as needed and form will fail due to self intersecting  

[Anonymous]

Yeah, sorry about the images, i made it with randon dimensions just to exemplify my point that depending on the cable length i would have a problem with the parameters, because some of my middle points might get behind the fix point at 1.9 meters segment lenth making it impossible to create form. The problem is not with amout or place of the adaptive points, because they only define the shape of my spline (of course it is important, but in this it is not what is making problems), but it is with the points that are hosted to my refence line, the ones that control when cables are close to each other or not.

[RDAOU]

I think you didnt get my point... in the example only 6 points were used to control the left and right rails... in reality you will have 100s of points constraining those rails

Additionally if you would be using dynamo, the points hosting the rails would not be the same points hosting the profiles...I'm not at my desk at the moment, when I get back I will try to find time to create a more realistic example for you

[ToanDN]

Why do you need to create 3 separate paths to begin with?

[Anonymous]

Sorry about the drawing, that is what i could do by now hahaahhaha.

What i need is to have a group of 3 cables, in the middle they are side by side (touching each other). In the edges of the cable i have a fix length of 1.9 meter where the cables separate from each other.

[ToanDN]

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@Anonymous wrote:

Sorry about the drawing, that is what i could do by now hahaahhaha.

What i need is to have a group of 3 cables, in the middle they are side by side (touching each other). In the edges of the cable i have a fix length of 1.9 meter where the cables separate from each other.

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Okay.  Is it a different question from your original one because they look nothing alike and these 3 cables in this sketch are certainly not parallel.  

[Alfredo_Medina · Accepted solution]

I think you already have enough information to do your task, don't you? Create adaptive points for the main segment. Then define all the other points by projecting points left and right from the main segment, then do the same for the ends. Then connect the dots. 

[Anonymous]

Unfortunately not. Because of this problem, my family has to be able to work with 100 meters cables and 20 meters cables.

[Alfredo_Medina]

Divide the problem in 3 parts. Fork "A" and one end, intermediate segment, Fork "B" at the other ends. Those require different techniques, which have already been mentioned in this thread. 

[vishalshiyal20121999]

How you vary your tendon length give me some idea about that because length parameter is not work in adaptive model