"Point On Curve" : isn't it redundent with "Evaluate Length" with "Normalize Length" option On ?

I can't see the utility of the "Point On Curve"" function : Point_On_Curve.JPG

To me , it is identical to "Evaluate Length" with "Normalize Length" option, and a slider.

At the same time, I find that a function that would give directly the Min and Max parameter of a given curve would be more useful.

Cheers,

Olivier

Replies to This Discussion

Permalink Reply by Dedackelzucht on August 18, 2011 at 2:49am

Hey,

a simallar discussion you can find here.

http://www.grasshopper3d.com/forum/topics/learning-data-trees?comme...

Best Regards

DeDackel

Permalink Reply by Danny Boyes on August 18, 2011 at 2:51am

I'd say that whilst they are the same output one is the advanced version of the other.

Point on a curve's pros include the fact that it is only one component, the right click menu option to select default locations along the curve, the fact that you don't have to make sure the Boolean value is set to you intended option and its cons are there are no Tangent or Parameter output.

So if you need T or t then you will have to use the more advanced Eval Length Component.

Edit: Also a pro is that its default is set to mid point. So its very quick to drop a Point on curve component on the Canvas every time you just need to know the midpoint of a curve without having to go through the process of slider>move slider>Eval Length> hook up wires between slider and eval length for the same function.

Permalink Reply by Olivier Suire on August 18, 2011 at 3:07am

Hi Danny,

I understand the pros and cons, but in many cases, Grasshopper forces you to use advanced functions to do simple things.

This allows to keep the number of functions to the minimum.

But in this particular case, I feel that it would have been more interesting to have a function that would give directly the Min and Max parameter of a given curve.

In fact, it takes more components to acheive that than what "Point On Curve" does...

Cheers,

Permalink Reply by Danny Boyes on August 18, 2011 at 4:44am

I'd say make a wish.

How many components are you using?

Permalink Reply by David Rutten on August 18, 2011 at 6:25am

[Domain Components] does exactly that. When you feed a curve into a Domain parameter, it automatically converts.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Olivier Suire on August 18, 2011 at 8:11am

Hi David,

Then ,the next thing I would like to see more than "Point On Curve" would be "Curvilinear distance of point on curve from origin of curve".

Explanation : When a point is on a curve, it would be nice to know what is his distance from the origin of that curve, following the curve.

Perhaps an extra output to "Curve CP" ?

I'm not even sure how to do that with a combination of existing components.

Perhaps with the "parameter on curve domain of closest point", plus "Evaluate length", using as Length Factor the ratio between the said parameter and the max. parameter of the curve.

But I found that using the parameter domain of poly-curves a bit strange...

There is no apparent logic in the values of the lowest and highest parameters.

Why aren't those parameters systematically re-scaled to o->1 instead of funky values ?

Cheers,

Olivier

Permalink Reply by Danny Boyes on August 18, 2011 at 8:21am

You can do this with using Evaluate Curve output L.