Create a parabola curve

It's maybe a stupid question but I don't find the tool for creating a parabola curve...within Rhino there is a tool for building parabola based on vertex and direction but I don't find the equivalent in GH.

Did you ever faced this issue?

thanks in advance for your answer,

Replies to This Discussion

Permalink Reply by TomTOM on August 7, 2014 at 1:11am

Ok, I made a mistake... I'd like to control the focus instead of the vertex.

Sorry my issue wasn't clear.

Permalink Reply by Pieter Segeren on August 8, 2014 at 4:11am

Ah (ggghrr), well, I fumbled this together for you to test (I bearly did). Notice the VB component is really bodged together, however it does produce the same result.
Please let me know if it's any good.
Have a nice weekend.

Attachments:

Parabola_byFocusDirectionPoint_PSG.gh, 34 KB

Permalink Reply by TomTOM on August 11, 2014 at 2:11am

Perfect! thanks again for your support!! I've to learn VB looks really powerful.

Permalink Reply by TomTOM on August 11, 2014 at 3:50am

There is something I don't understand. I'm using your VB with others blocks around and indeed parabola from your script is the same as the parabola from Rhino but my final results after few functions are not anymore consistent.

attached you will see my GH file and the curve in Rhino.

play with both and you will see that results after my scale tool and really not consistent and I don't know why...looks that the orientation plane isn't the same...it's weird because with your previous VB (with vertext parameter) results were good

Attachments:

test.gh, 33 KB
test.3dm, 26 KB

Permalink Reply by TomTOM on August 11, 2014 at 4:03am

I found the trick by applying a reverse before the scale. I don't know why exactly it's not done in the same direction but it's working now.

Permalink Reply by Pieter Segeren on August 12, 2014 at 5:02am

Glad you like it TomTom. Notice the approach using the native GH components, try to understand the math first ( it's not VB that's powerful;) )
In an attempt to assist at finding the answer to your "test" file, I added an output for the parabola base plane. I admit that I didn't understand your goal though... Also, I used the wrong icon before (indicating the vertex), here's a better suiting one.

Attachments: