Boolean Pattern from Intersection Operation

Replies to This Discussion

Permalink Reply by to] on October 30, 2009 at 12:12pm

hi pat

you have to write a vbnet component
this is just the pseudocode :
RhUtil.RhinoCurveBrepIntersect=false then ... add curve to a new list
thats all --- the result is a list with all the curves not intersecting your geo

best to]

Permalink Reply by Patrick Bedarf on October 30, 2009 at 1:17pm

cheers my personal superhero!

Permalink Reply by Sameer Kumar on October 30, 2009 at 3:49pm

There is also a simple and purely GH way of achieving this if that is of any interest.

Permalink Reply by Patrick Bedarf on November 1, 2009 at 9:55am

Mmh...I will have a look at this. Cheers mate pat

Permalink Reply by Patrick Bedarf on November 1, 2009 at 11:43am

Hi Sameer

first of all thanks for the response. I've tried your strategy with the following problem occuring: my input curves are stored in 25 several lists (which are needed later on) and I'm facing a pathing problem.

The BCX is giving me the intersection pts all pathed (in my case 600) which I have to use for retrieving the item inside the tree later on. I think all it needs is to split the tree of intersection pts in 25 branches but I'm so far too dumb to get it :(

I'll attach the def so maybe you'll give it a try

thx pat

Attachments:

• visibility def_alternative.ghx, 166 KB

Permalink Reply by Sameer Kumar on November 2, 2009 at 6:04pm

Pat,

To get the intersection command to preserve your paths, you need to get the data tree structure of the curves and that of the brep to match. See intersection-a.jpg where I have simplified the curve data tree and grafted the brep. As you can see, the result is giving me 24 paths...

However, this will not help you in singling out the lines that intersect the brep. To be able to check each line for intersection, you may need to flatten them out completely. As you can see in the image above, the number of intersection points are per path and not per curve. If you look at the image below however, the 600 paths tell you a different story which can easily become a cull pattern. All you have to do is to flatten the lines entering the cull-pattern component.

Permalink Reply by Patrick Bedarf on November 3, 2009 at 12:32pm

Exactly. Without having a deeper look into it again its telling the same story as I mentioned earlier. The problem is that I need the path structure later on to point out how many lines in each point are intersecting the brep :(

So thats the crucial point I have to work on. If you got an idea how to match the path structures let me know - I'll play around this night so hopefully things will be clarified asap

cheers mate . pat

Permalink Reply by taz on November 3, 2009 at 1:18pm

Pat,

You might be able to extract something from the "intersections" portion of the grillage definition I made. It's checking for all surface/surface intersections that occur.

definition guide

It's a bit too complicated to try to explain the routine with words, but if you have specific questions I can (maybe) explain what I was thinking.

-taz

Permalink Reply by Aida Ramirez Marrujo on September 22, 2011 at 11:38am

I have a similar problem, I have some lines and a Brep and I want to select the lines that don't intersect the Brep, I was thinking also in some kind of boolean but I really don't know how to do it... Any suggestions?

Permalink Reply by Sameer Kumar on September 22, 2011 at 12:38pm

Aida,

Look at this thread:

http://www.grasshopper3d.com/forum/topics/curvebrep-problem

Hope that helps.

S

Permalink Reply by Aida Ramirez Marrujo on September 23, 2011 at 9:01am

Sameer, thank you! It was very helpful!

 

-Aida