Track point trajectory in order to generate an interpolated curve

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Permalink Reply by David Rutten on September 13, 2010 at 1:21pm

Hi kVVV,

I haven't looked at the file, but could you not generate all the solutions instead of just one? That way you would get all the points and you can connect them with a polyline/curve.

If this is not an option, there's no mechanism inside Grasshopper to maintain data between solutions, so you'd have to code up a VB or C# component that can do this. It's not terribly difficult, but it does involve custom code.

You'd also have to think about what needs to happen when you want to destroy the old data.

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Igo Kommers Wender on September 13, 2010 at 2:07pm

David, when I say to track the trajectory of each point in order to generate an interpolated curve from each point trajectory I mean it is just the base solution to be later applied to another points.
But what I do not know is how to maintain the destroyed data when I move the point from one place to another with the slider (Imagine you are walking in the sand and while you move your footprints are being left behind you. These footprints would be the the trajectory that would make possible to generate the interpolated curve or a polyline). Sorry about these flat explanation, but it is a bit difficult to explain that in english
If the only way to do this is to code up in VB o C# I will have to wait a bit longer because my knowledge in coding is inexistent.
Anyway if you have any other idea to get this, please let me know. I would love to solve this.
Thank you very much,
kVVV

Permalink Reply by Andy Payne on September 13, 2010 at 9:03pm

Hi kVVV,
There is a Data Log component in the latest build of Firefly (ver. 1.003 from www.fireflyexperiments.com) which allows you to track any type of data and store it in a list. It has an optional parameter which allows you to specify a file path so you can write the data directly to a text file. In addition, there's a new Playback component which allows you to recall a given text file, and return each individual line at a given frame rate. This should do exactly what you're looking for.

Permalink Reply by Igo Kommers Wender on September 14, 2010 at 11:31am

Hi Andy. Thank you very much. It works great, therefore it is exactly what i was looking for. Amazing components!!!
Cheers,
kVVV

Permalink Reply by benjamin jenett on September 27, 2010 at 4:45pm

Hey what aspect of firefly did you end up using? I am hoping to pretty much do the same thing as you for my own project-- great to hear you got it to work!

Benjamin

Permalink Reply by Igo Kommers Wender on September 28, 2010 at 1:48pm

Hi Benjamin. I used the Data Log component of Firefly. The Data Log component has 6 inputs and 1 output which is the tracked list data. I used it to track the movement of some points and construct with them an interpolated curve (something like a trajectory path of a point)
Inputs:
V: The incoming data to track
R: Reset the log of values (True or False)
S: Star recording into the values (True or False)
W: Wrap index to list bounds. (I leave it in the default setting)
L: Set the number of values you wish to store in the data log. If you set 0 it will record indefinitely until you stop the recording.
P: Optional file path (In my definition it was not necessary)

This information is basically the same you will find when you hover the mouse over the individual parts of the component. I think, if you need, you can find more detailed information in the Firefly Primer which can be downloaded from the Firefly web page (www.fireflyexperiments.com).

Hope it helps,
Igo