Rhino curve to Grasshopper

hey, I'm currently in learning process of grasshopper. And I have set myself a task. Having a curve, created in Rhino, and the parameters, to create the curve in Gh, in such a way that I would be able to modify these parameters (as in modify the position of a point or a angle resulting with the modification of the general shape of the curve). I did manage to create the curve, but i cant seems to find a way to extract those parameters so that I can change them. Nor could I seem to find an answer which would help me with the task.

For example having the 'Control Point', it helps me with creating the curve, but not with modifying the position of those points , so how can i extract those point? or in case of the shape on top how to modify the angle between the 2 lines.

Here is a screen of the shape that I'm trying to modify and reshape.

Thank you beforehand :)

Attachments:

detail.3dm, 176 KB
detail.gh, 14 KB

Replies to This Discussion

Permalink Reply by Gangura Petru on October 10, 2015 at 3:52pm

the attached files: the curve drawn in Rhino, and the algorithms I tried. now trying to something with 'Item List', but for now, cant figure out, how to change certain parameters of the figure

Permalink Reply by Gangura Petru on October 12, 2015 at 12:29am

Please :( anybody??it would really save my life in a way, knowing how to adjust the parameters of a rhino based object in grasshopper (just displacing the control points and angle)

Permalink Reply by Nik Willmore on October 12, 2015 at 2:40am

I don't understand the question. I think you are both over-thinking how to approach a problem and under-thinking about how to totally reformulate your question in a way that better "fits" how best to think in Rhino/Grasshopper.

First, it's not a simple thing to grab existing Rhino objects into Grasshopper, except for the Geometry Pipeline component. I like to do that myself, since I often think of Grasshopper as a way to add functionality to normal Rhino use, for normal Rhino users unfamiliar with Grasshopper. But it's often not easy, lots of trial and error being required.

Since you are new to Grasshopper, you have the advantage of clear thinking before you suffer falling into the existing paradigm of utter compromise, but also you lack a vision of how the existing paradigm is also powerful.

Here is how to grab the existing Rhino geometry into Grasshopper, avoiding Python etc. scripting, just using Geometry Pipeline. I right clicked Pipeline to grab curves, via the pop-up menu, and also set the Layer filter to Default. I'm also right clicking components ("nodes") to shut off Preview of intermediate ones, which is why they appear dark on the canvas.

To find Geometry Pipeline in the vast array of nodes from the toolbar, I just double-click the canvas and start typing Pipeline, and select it from the pop-up menu, which places it on the canvas:

Also, you are running points through a Panel, which you can't do since a Panel will turn the point data into text. Sorry, but I didn't write Grasshopper.

Yes, the learning curve for Grasshopper is very steep and it's indeed the little things that will trip you up for month after month.

So that's entry level step one: getting info from Rhino into Grasshopper. Normally, users here wouldn't much bother with that, but would just define from scratch the geometry in Grasshopper to begin with, so you then already have access to the generative features of it. Or, they would immediately move the geometry into Grasshopper by right clicking a Geometry node and assigning and also internalizing what they made in Rhino, but that does miss making it in Grasshopper from scratch, so indeed needs much work to extract details from.

Above, I merely moved your points. Next I'd have to recreate your lines, then start isolating the middle points to just move them, etc.

Attachments:

detaiBl.gh, 15 KB

Permalink Reply by Gangura Petru on October 12, 2015 at 5:10am

Now that you pointed it out. I do agee that the question is rather unclear. Basically, I am wondering whether you can take a shape build in rhino and reference it in Grasshopper.
Afterwards, being able to adjust the parameters (such as : line length (between points)/angle/fillet).

Permalink Reply by Daniel González Abalde on October 12, 2015 at 5:07am

Here you have a method but this is not delicious food for grasshopper. If you want to move individual Control points, it may be best done from Rhino.

Attachments:

detail.gh, 20 KB

Permalink Reply by Gangura Petru on October 12, 2015 at 7:11am

Thank you so much, it is exactly this what I meant, but I am afraid that as a beginner, it would indeed be better to create the shape from scratch on grasshopper. Using basic commands, thus having more understanding of whats happening. regardless that I do understand more or less , but as far as I can see, for Grashopper , you have to have a rather deep understanding of the processes, in order to control it better .

But thank you a lot!

Permalink Reply by Gangura Petru on October 12, 2015 at 5:17am

Or maybe create the same shape from scratch in grasshopper... I was just thinking that it would be faster, taking the rhino shape. Extract control points. And modify the data around those points. But I couldn't find any way to indicate which points to connect. Because what it did for me: it connects every points between each other. Thus create a chaotic set of lines involving those points...

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