rectangle origin

Is the rectangle (curve>primitive) origin supposed to be at the lower left vertex or in the center?

I'm following this tut: http://web.mac.com/rhino3dtv/GH/GH_10_18_Inter_Demo_3D_Rec_Tile.html

but I'm a bit confused, on the tut the behaviour is different from what I get on GH.

here the images of the definition and the result.

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Replies to This Discussion

Permalink Reply by David Rutten on February 7, 2011 at 2:21am

Neither. A rectangle is defined by a Plane and two intervals along both axes. Thus, the origin point could be anywhere. Though if I make the Rectangle I always try and pick a sensible origin point. Also, the rectangle type in RhinoCommon has methods to re-center the origin point at any of the corners or any arbitrary point on the base plane.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Alessandro Guida on February 7, 2011 at 4:01am

Hi David,

thank you for your reply.

found a possible solution though seems overelaborate:(

Attachments:

ScreenClip.png, 34 KB
rectangle origin.bmp, 1.1 MB

Permalink Reply by Danny Boyes on February 7, 2011 at 5:13am

Hi Alessandro,

Instead of supplying a number to the rectangle inputs use a domain to define the start and the end interval along the plane. Here I've shown an example using a slider combined with some F(x) components to get a negative and a positive start/finish to place the origin in the centre.

So the difference is that GH is converting your input of 1.0 into a domain of 0 to 1 in the first instance but because it doesn't have to guess for the corner ones you get what you intended.

Permalink Reply by Alessandro Guida on February 7, 2011 at 5:32am

Hi Danny,

thank you! that works better (and clever)!

Permalink Reply by kleerkoat on February 7, 2011 at 10:42am

quick question, you might have explained it, but i don't quite understand what the domain component is that the functions get plugged into is doing?

thanks.

Permalink Reply by Danny Boyes on February 7, 2011 at 11:06am

A domain is the start and finish of a range/interval. In the example below there are three domains to create three different rectangles about the same plane.