"unfold" thickenened polyhedra to create mitred edges

Hi everyone,

Please be gentle, I'm not massively versed in Grasshopper, and I apologies if this is obvious.

I am trying to create a patch which generates irregular polyhedra solids, then thickens the surface and unfold them with mitred corners. This is to hopefully subsequently gut then musing height maps, where the mitres are marked out with linear gradients.

I have had some success creating the forms, and the offset surface by using weaverbird, but I can't make an offset surface [like the offsetsrf command in rhino] on a brep in grasshopper [brep to surface conversion failed]

All said, I am at a loss as to how to proceed next, I appreciate my patch is super simple so far.

Approaches I am considering:

1) Explode the "surfaces" of the brep into edges >>> attach [somehow] the internal surface to the external surface so it remains in the same position relatively when flattening the external surface

2) Split the "solid" created by the 2 surfaces between the two seams to create n surface panels that include the mitre

Please could someone advise the best approach to take, and if you can point me to any learning resources that might cover this, I'd love to know.

Thank you in advance

Nick

Attachments:

polyhedraOutlines.gh, 11 KB

Replies to This Discussion

Permalink Reply by Stefan on April 2, 2017 at 5:31am

Hi Nick,

the Offset-component only works on surfaces, you can use 'Deconstruct Brep' to make it work.

This will however split up your polyhedron at its seams and I'm not sure that is what you're going for.

Maybe a simple Scale will be enough for the first step - check it out

-Stefan

Permalink Reply by Nick Diacre on April 2, 2017 at 2:10pm

I have used the scale to create a second instance, good tip. I am trying to loft between the individual faces of the two breps [using debrep] to create solid "facets", but the loft is failing...

sorry this is probably basic stuff, but I have tried searching, any advice would be much appreciated...

Attachments:

polyhedraOutlines.gh, 10 KB

Permalink Reply by Nick Diacre on April 2, 2017 at 5:53am

Hey Stefan, thank you for the reply. Scale was cool, but this is for laser relief into materials of a specific thickness, so offset was ideal as it determined the thickness of the material. That said I could create a Boolean function upstream *if* I can work out how to unfold the solid along the mitres.

Permalink Reply by Nick Diacre on April 3, 2017 at 4:52am

For those that are looking for a solution to this in the future, here is what I did... creating individual breps with miter