I tried to offset multiple open breps (basically veronoid cells with each face hollowed) in grasshopper.
Rhino command “Offsetsrf” does the job perfectly (extruding the surface into direction of the normal at every point), as shown at right side of image, but I failed to find a grasshopper equivalent to it.
I tried following methods, each has its own problem.
Pufferfish OffsetSurface: it breaks the open brep into multiple planar trimmed surface and extrude them individually.
unfortunately there is not always a feature found in rhino accessible from gh. quite often these features are very complex algorithms, so its nearly impossible to rewrite them.
if you are familiar with winapi hacking you can at least fake a manual input.this is what I do in catia all the time in order to get access to uncallable features. Another option, bake and manually do it or simple do what the algorithm does for your specific geometry, extend and trim.
Pufferfish OffsetSurface: it breaks the open brep into multiple planar trimmed surface and extrude them individually.
Because it is for surfaces, not breps, as the name implies
Rhinocommon for R6 added offset brep method however brep offsets in general usually have many problems. Better to think about the construction of the geometry as a solid at the start of the process, rather than rely on one algo to solve the thickness for you afterwards. Anyway here is the method. https://developer.rhino3d.com/api/RhinoCommon/html/M_Rhino_Geometry_Brep_CreateOffsetBrep.htm
Yea, I considered to add it to Pufferfish, but as you know this brep offset fails often or makes weird edges, not even Rhino’s fault so much, as you said it is a tough problem that rarely needs such a general solution. I didn’t want the emails complaining that it doesnt work from people not understanding why it doesn’t work
I sense irritation there. My sincere apologies. You can be assured that this is definitely not a complaint but a factual statement of confusion. And the free stuff is, on the contrary end, deeply appreciated here. After all, not all drivers are mechanics by training and sometimes they make stupid assumption about cars. Anyway thanks for both the reply and the lecture.
Err… and what if you don’t know the least bit of coding ?
I naïvely copy-pasted this in a C# component, and got some grumbling about a “;” missing somewhere.
