Grasshopper

algorithmic modeling for Rhino

# Domain Component or Surface dimension incorrect

I generate a surface from edge, but if i analize the surface dimension or domine component i have an incorrect value. Anyone know why?

Views: 2208

Attachments:

### Replies to This Discussion

What's incorrect about it?

--

David Rutten

david@mcneel.com

The vertices of plane are correct because i have a surface of 10*10, but if i compute the U and V domain or U and V dimension i have an error, because it compute from -0.1 to 10.1. You know why? thx

The PlanarSrf component will take input curves, create a surface that extends beyond the edge curves and trim with the input curves. That's why the domain of the surface is larger than the domain of your border rectangle.

There's a surface primitive that creates a rectangular plane. This surface will be untrimmed.

and how i can resolve this problem?

By using the a surface component which doesn't create a trimmed surface. For example [4Point Surface] or [Plane Srf].

--

David Rutten

david@mcneel.com

Hi,

I have the same issue for this surface dimension box. As I look at the description of this box it says "Get the approximate dimensions of a surface." which I understand this as I should not rely on this box as it will give me just the approximate results anyway.

So at the picture below I have a planar section, which I couldn't get the results that I want it like to be in the rhino dimensions.

Which way could you suggest me to pursue of ?

First of all, the Surface dimensions will return the length and width of the underlying untrimmed NURBS surface. If this surface is rectangular, the dimensions should be pretty good.

From the look of it, your input surface is a trimmed surface. Probably, the untrimmed surface extends a bit over your border curves. The Rhino command ShrinkTimmedSrf should make the results a bit better...

if you don't want to rely on surface dimensions, use a Bounding Box. Extract the length and width by deconstructing the box.

Aa yeah shrink surface to the edge gives more accurate dimension values now. Thank you very much !

Besides, your other method gave me the coordinates like -x to +x which i have to subtract to find the exact value. Are there any more simplified of this method to get the exact values like in the previous one ?

Well, you could plug the Domain output directly into a number input (or param). That will implicitly convert the domain into its length. Basically, what you are doing right now, just behind the scenes.

Be aware that math components don't have number inputs but generic data inputs in order to handle vector math. So those inputs will not automatically convert the domain.

Okay now i work it out.. But for the param you meaned param viewer or the tab params ?

If its param viewer it didnt work well like the number maybe you meaned something different but whatever i got to my point anyway.

Thanks I appreciated so much !

Param as in Param Tab

by June Lee

• View All

## Videos

• ### Tree Columns structure (Grasshopper Tutorial)

Added by Parametric House

• ### Inflated Hexagon Pattern Rhino Grasshopper Tutorial

Added by June Lee

• ### Al Bahar towers Facade (Grasshopper Tutorial)

Added by Parametric House