Grasshopper

algorithmic modeling for Rhino

# How to add collider geometry

I find WASP to be a really cool tool to create aggregations. I worked with it throughout the semester and learned what it can do. However I cannot figure out what to use for the COLL input on the Basic Part..

I use some geometry that's more complex and that can't be replaced by a simpler one (to be replaced later by more advanced shapes).. and the aggregation parts intersect since they only see the parts they are connected to but not the others.

Can I use the COLL input to solve the problem? I tried transforming my parts into meshes and using those as inputs but it didn't work.. Is there any other way to solve the problem?

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### Replies to This Discussion

yes, the COLL input is there to help modelling with more complex geometries. Generally speaking, the collider input should take a mesh which is slightly offset inwards from the original geometry (0.01 units for example). This allows to avoid computing intersections with the connecting parts.

It is a bit difficult to be specific about your problems without seeing the geometry you are working on. If you could attach here one example of the geometry you are working on, I can try to see if it is possible to build a collider for it.

Hi Andrea,

thanks for the quick reply! I have managed to simplify almost all of the parts, so that the Basic Part doesn't give an error message regarding the collider (although the final aggregation results might be affected). One piece however I still cannot manage to simplify enough..

From left to right the pieces are B, 2RA, 3RA, 4RA, 5RA, each with their more complex variations underneath.  5RA (on the far right) is still presenting problems. (I attached the Rhino and Grasshopper files)

I will try to see if I manage to solve the problem with the inwards offset mesh, as you suggested.

Attachments:

see the attached files. I computed a collider for the last part in Rhino, using OffsetSrf with a distance of 0.01, offsetting towards the inside of the part.

I run a stochastic aggregation and it seems to work fine. I just used all possible rules combinations, so you might want to define rules in a more precise way to control the result better.

I also added a color attribute to each part, so to easily visualize them while you work on it.

Aggregation_RV_editAR.gh

Hi Andrea,

sorry for the late answer.. I had figured it out a bit after you replied the first time and added some extra geometry too to keep everything in check. And yeah, the extracting component is also great when you have to actually render the architecture that comes on top of the aggregation.

I have to thank you a lot for creating WASP, it's a very intuitive tool for quick aggregations.

This thread saved my life! I couldn't make the collider work properly and now I know why...it was exactly following most of the edges of the actual part geometry; after a slight inward OffsetSrf i finally made it work! Thanks a lot Andrea and Vlad