Naughty Edge Offset

Replies to This Discussion

Permalink Reply by Choco Choc on March 24, 2011 at 5:59am

Up !!

Permalink Reply by Danny Boyes on March 24, 2011 at 6:25am

There has been quite a bit of discussion recently on the implementation of the offset routine in the latest Rhino.common release. Two solutions that have been put forward are the offset both sides and then cull the larger/smaller result. Or to offset on a surface (which is much slower to solve.)

BTW the Plane Origin component was just to demonstrate moving a plane rather than a point. It is not necessary to do this. 

Permalink Reply by Choco Choc on March 24, 2011 at 11:03am

I did it with length, but it's longer to set up.

I attached my version of the script.

 

Thanks

Attachments:

• offset selectionner.ghx, 210 KB

Permalink Reply by Choco Choc on March 24, 2011 at 7:41am

Hi Danny,

 

Thanks for that solution, it's working pretty well and I could learn a little, but there is still one case, that I can't solve, and that's  the one I need :

 

In the Digital toolbox video tutorials (made with a previous version of GH) they make little tabs for fabrication of a panelized surface like this :

 

 

As you can see, they offset the curves without joining them, so they can scale them a little (something like 0.80) and so they join them to the triangles, getting that particular shape.

 

So I need to offset without joining, so I can scale the edges the way I want...but when I take of the join button you made, since the comparison ">" won't work anymore with the areas...I still get the same problem :

 

 

As you can see, still only the centered face is offsetting correctly, and I wonder why, since I still indicated the offset as the new plane you created at the center of each panel...

Permalink Reply by Danny Boyes on March 24, 2011 at 8:05am

You can use a similar type of culling pattern but instead of area comparison use the distance to the centre of the new line. Smaller than original get ride off and Keep larger than original.

Make sure you set the data Matching of the Offset Component to Cross Reference on the context menu.

Permalink Reply by Choco Choc on March 24, 2011 at 11:05am

Thank you for your help, just a last question...there are two buttons I can't recognize since I'm all new to GH.

 

It's : the button displaying the 0.50 value and the button just right next the offset button with the a b c i values...

 

Thanks again !

Permalink Reply by Danny Boyes on March 24, 2011 at 11:14am

Sorry, The 0.5 value is the Curve Point Component Curve Tab>Utility Section and the ABC is the Pathmapper. It is located in the Sets Tab>Tree section.

When you put it on the canvas it is blank. Double Click it and put {A;B;C}(i) on the left hand side and {A;B} on the right hand side.

What the pathmapper does is re-map the items and branches. In this case there are single items on the last branch {C} for each surface. What we want to do is collect all those items on to one level {B}. Effectively Flattening the branches without destroying the tree.

 

Permalink Reply by Choco Choc on March 24, 2011 at 12:38pm

Thank you for the indications, that path mapper seems very powerful, I used to flatten then regroup with series etc... a long job.

So in fact the {0;0;0} etc are designated by {A;B;C} ?

But in the panels it seems to be A that is always stuck to 0, so why do we get rid of C ?

Or does it just mean take the two first values from the right ?

 

I'd like to know more about the syntax used inside, ins't there a documentation for this ? I'm also looking for some clear infos about flatten cross etc...I understand what crossing does to 2 series of points...but that's all.

 

Whatever, I followed your script and I crossed the offset's references but I still got the same problem...so it turns to a "where is waldo" game, and I'm convinced I made everything properly...

 

I'm sending my files if you have time to check I'd be grateful..

 

Thanks

Attachments:

• waldo.ghx, 113 KB
• waldo.3dm, 53 KB

Permalink Reply by Choco Choc on March 24, 2011 at 1:16pm

by the way there is something to do with the basic surface...

 

For example if I erase everything but a surface that has bad offsets, and select it as the surface for the brep, then the offset works well...

Also, when I delete one of the surfaces, the offsets on the other surfaces change....and also, as from the beginning, when I move a surface, the offsets change...sometimes correct sometimes wrong...

 

I don't understand why can't we just use the p parameter of the offset button, whatever I feed it, it doesn't change a bit...