Grasshopper

algorithmic modeling for Rhino

Hi all!

 

Having some problems pointing my surfaces normal in one uniform direction. I'm trying to generate an inner surface for this folded geometry (similar to a 'shell' operation) to eventually be left with separate panels. I'm starting with the intersection  points at each of the surfaces corners. I'm thinking if i can find the  'average' vector direction at each intersection point I can use this to generate the intersection points for the inner surface (or outer)... 

 

 

The problem is once I start to evaluate the surfaces that share each intersection point, their normal's appear to be pointing in different directions.. I have been through many discussions on the forum which have raised similar issues (including flipping curves and surfaces using guides) but having no luck resolving the problem. I have attached a definition showing my approach... Is there another way? can anyone help?

 

Thanks

 

Dean  

 

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I was thinking that you generate a vector from the reference point to say the start point of the normal vector and then test the angle between the two vectors and make sure they are less than pi/4. The method you described will create positive vectors because they really aren't considering the direction of the surface, but simply using the points as basic inputs for making a generic vector.

I did something similar here for a set of curves to make sure they were oriented in a clockwise manner.
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Sorry should be less than pi/2 in your case if you use the reference point as the start.
If i remove the reverse x axis and make it less than pi/2 I get two faces still flipped... getting close!




Could it be how the surfaces are generated after using planar component?
image attached
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I think you mostly got lucky! XD I didn't mean for you to incorporate the file I gave you exactly, but rather to use as an example. I meant for you to compare the angle of the two vectors in a similar fashion as I did, not apply the sample to your curves. Try the file I posted below, it may need some tinkering still.
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A seriously big thank you to both Vicente and Shawn for their help – turns out the 2 definitions are very effective at solving the problem in very different ways.


Vicente, the script component has saved valuable time by computing the normals.


Shawn, I used the pattern from the flip component to reverse some of the lines between the two vectors I generated, it worked a treat!


Definition images attached
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Sweet! Glad I could help. There's usually more than one way to get to where you need to go. =)

Hi, I really don't want to bother anyone in old threads, but it seems to be exactly what I'm looking for.

The problem is that I just started in GH and I can't recognize all this icons from definition. Would you mind to post the image with the full names, please? Thank you!

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