Grasshoppper will not sweep

I'm creating a screen and I'm trying to sweep along a rail and for some reason grasshopper won't sweep along the rail with sweep one. Both inputs have vaild planar curves but once put into the sweep 1 there is no values being inherited into the sweep for some reason. Can anyone tell me why this is. I'm a new user so this may just be a simple fix but I'm not seeing it. I'm using wip 6.0059.

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WontSweep.jpg, 444 KB
WontSweep.ghx, 183 KB

Replies to This Discussion

Permalink Reply by to] on February 13, 2010 at 10:36am

hi matthew

you have to flip the rail curve
because she points in the direction of the section curve

Permalink Reply by Vicente Soler on February 13, 2010 at 5:05pm

so curves are female, makes sense. i guess polylines are male.

Permalink Reply by Matt on February 13, 2010 at 10:55am

Awesome. Thanks. For future reference is there some rule to go by. I'm assuming the start of the curve has to also be the start of the loft? Sorry for all the questions?

Thanks

Permalink Reply by to] on February 13, 2010 at 11:11am

hi matthew

keep always in mind that the domain of curves and surfaces are very important on parametrical driven processes
they define start and endpoint of geometry
so in your example the curve had to sweep beyond their domain so it was not possible to create geometry

Permalink Reply by Ben Fortunato on February 15, 2010 at 1:33pm

I was having similar problems, but It seems that the sweep will not work on closed curves. Is this correct? . . . And if so is their anyway to get around this?

Permalink Reply by Ben Fortunato on February 15, 2010 at 1:37pm

. .. . I was also wondering if their was a way to adjust the direction of a set of curves so they are all facing the same way? Perhaps this would help the sweep component be more reliable?

Permalink Reply by to] on February 15, 2010 at 2:22pm

hi benjamin
it is of course a topic of failure trap which should be corrected or you have to create the curves in the right direction (domain 0 - 1)
so you have the same error than matthew. create a cull logic for the curves which have not been sweeped and than flip the culled curves and sweep them again.
hope that helps for now

Permalink Reply by Ben Fortunato on February 15, 2010 at 2:51pm

I experimented with the above, just duplicating the sweep procedure for simplicities sake for now. I can't get all the curves to loft. I tried doing it four times to cover all the possible combinations of section and rail curve orientations but their are still some curves that will not sweep. Is their a way to do this through a VB component or is this too complicated? . . . . .Whatever coding went into the grasshopper sweep component it doesn't seem as tight as the procedure called through the Rhino command sweep. . . .Is their a way to use the Rhino sweep? I couldn't find it in the Rhino.util classes. .. . .

Permalink Reply by to] on February 16, 2010 at 2:10am

hi benjamin

the function is RhUtil.RhinoSweep1
sure it is possible to write it on your own
you have to implement that if the function fails flip railcurve (don't forget to write a break)
have you tried to cull them and flip the railcurves?

Permalink Reply by Ben Fortunato on February 16, 2010 at 8:32am

I just duplicated the function four times flipping wither the rail, section or both curves. This did not successfully sweep all the curves!?. . . . I can try to cull the curves as this might produce a better result, but I'm not sure how I would generate a Boolean list of true and false variables based on whether or not the component executed. Would this be something I would have to VB Script (I think I can figure this out based on whether this list has empty or null values) or can I do this in Grasshopper? . . . . . .

This is a pretty important function that will be used all the time, for structure, mullions etc. Its a shame that its not more user friendly.

The RhinoSweep1 command looks like it might be over my head, I wasn't sure what to make of the arguments in the SDK:

Public Function RhinoSweep1(args As MArgsRhinoSweep1^%, brep_array As [System::Runtime::InteropServices::Out]array^%) As bool

When I look at MArgsRhinoSweep1 their isn't a lot of info. . . I'm looking for a method that takes in a rail and a section curve but I couldn't find it.

But as I mentioned before, this is one of the basics that should function well. Is David aware of this problem? I think some other people were having trouble with this component?

Permalink Reply by taz on February 22, 2010 at 4:12pm