Slider component?

hi there,

I’m new to grasshopper and currently looking up some tutorials etc.
I came across this component and cannot figure out where to find it and what it actually does:

can you help me out here?


point on curve. The length of the curve is represented as 1. So if you set that slider to 0.5 then you will get a point halfway your curve. 0.6 will you give you the point at 60% of the total length of the curve.

Looks like the Point on Curve component. Mostly used to give you a curves midpoint :wink: (set at 0.5).

It´s very importante to reparametrize the curve before use this component.

thanks for the quick reply and the explanation! :slight_smile:

thanks for the additional information!

The Point On Curve component uses length ratios, it doesn’t care about parameterisation. If you set it to 0.5, then the point will be exactly on the curve midpoint.

Thanks for the information David! I had some problems where I needed to reparametrize the curve, if I had the same problem again, I post the definition here. One more time, thanks a lot.

As David says, reparameterization doesn’t matter for this component but don’t try plugging it into Evaluate Curve as some have done. The value coming out does not correspond to the actual parameter at a point (unless, I suppose, the curve is a line)

No need, Point on Curve uses normalized Length, not parameters. You only need to reparameterize when using Evaluate Curve component because that is evaluating the curves parameter space (not the same as length). there is also Evaluate Length component which also uses normalized Length and doesn’t require reparameterization.

Edit: I see others beat me to it.

I noticed Pufferfish has a reparameterise curve tool. Is it possible to do this in GH without pufferfish?

Yes, with any curves input or output. Or in R6 GH1 there is a Curve Domain component. You can set the Domain to be 0 to 1.

So all you do is right click and select reparameterise? Grrrr!
Why have a component to do this?

For me it is just organizational / convenience. (Same reason why there is Graft and Flatten components even though that also exists in every input/output.)

Fair enough! I’ve learned something, albeit a bit obvious! Thanks!