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 5, 2014 at 2:08am

what I'd like to create is a parabola defined by the vertex, the direction and one point.

since I didn't find the tool for that I tried a parametric expression by unfortunately I don't have skill for scrypting...

hopping someone knows the trick

Permalink Reply by TomTOM on August 5, 2014 at 5:47am

Can i use the Graph mapper for building a parabola?

I saw the parabola function but I don't know how to extract the curve thanks to this tool...

Permalink Reply by Danny Boyes on August 5, 2014 at 6:07am

Permalink Reply by TomTOM on August 5, 2014 at 6:28am

Thanks Dany. but with this graph mapper is there a way to control these two points as inputs?

Permalink Reply by Danny Boyes on August 5, 2014 at 6:29am

No but you can manipulate the values after the fact to change the shape of it. similar to me using the slider "scale"

Permalink Reply by Danny Boyes on August 5, 2014 at 6:28am

I suppose because the X domain of the Graph mapper is 2 in length the Y should be set to 0 to 2

Permalink Reply by TomTOM on August 5, 2014 at 7:31am

ok thank you Danny, unfortunately I don't see how to use this tool for building a parabola based on vertex, direction and one point as it is possible within Rhino, graph mapper is probably a great tool but not relevant for my needs.

Permalink Reply by Danny Boyes on August 5, 2014 at 7:43am

Sorry your original question doesn't mention "one point".

Permalink Reply by Pieter Segeren on August 6, 2014 at 7:11am

Hi TomTom,
I've created a VB component that does that. It takes a Base plane (which origin is the parabola vertex), and a uv-point (on the base plane).
I also added my (old) User Object if you want to use only native GH components (and see the logic I used).
Hope this helps.

Attachments:

ParabolaPlanePoint_PSG.gh, 40 KB

Permalink Reply by TomTOM on August 6, 2014 at 8:34am

Hi Pieter,

thank you for your time and your proposal.

I played with your file and indeed you can create a parabola but not really like I want. I mean the joystick allows to rotate a parabola but I can't really define my parabola like in Rhino, that's to say Vertex, Direction and one point.

I also tried the "old object" but it the same conclusion.

Anyway thank you for this reply :)

Permalink Reply by Pieter Segeren on August 6, 2014 at 4:08pm

I combined the vertex and direction into one input: the base plane (the direction being the planes' Y-axis, the vertex its origin). But okay, changed it a bit to fit your input needs.

Attachments: