Grasshopper

algorithmic modeling for Rhino

Hello to the community, a few questions and suggestions

Hi guys!! 

I am completely addicted to GH. I've known about the software for a few years since I started modeling with Rhino, but only recently have I took the time to actually learn it. So many thanks to all the developers who are actually making my life a lot easier. Also, congratulations! This software, along with Rhino, is remarkably stable. I have had a great deal of nuisance using parametric modeling with other softwares. 

A few questions or perhaps suggestions, I am sure some of them are just because I am a little green on the subject.

- Is there any way to create a panel in Rhino with controls pointing to GH parameters, this way effectively putting aside GH window. When a definition is finished but you keep using it for varying the parameters and producing different results, it would be easier to do it with GH window minimised.

- What is the best practice for using GH with a Finite Element package such as Ansys or Abaqus? What may Galapagos contribute in the process of structural optimization/analysis.

- Just out of curiosity, has anyone ever used GH for fractal creation? Perhaps there is a plugin I don't yet know about.

All the best,

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Replies to This Discussion

1.  That already exists. Remote control panel. View> Remote Control Panel. To add parameters, right click on it and click to Publish to remote panel.

3- To fractals you need recursion. You can make loops with Anemona or hoopsnake plugin, or from code.

1: As Daniel said.

2: Elaborate more: list the apps that are in use in your practice and give a hint about the nature of designs of yours.

3: Speaking about fractals ...

PS: out of curiosity (that killed the cat) what are the other apps that you've tried and frustrated you?

best, Peter

Attachments:

I dont know about Ansys or Abacus workflow, perhaps someone else from this forum has tried it, but you can also try karamba plugin.

1) Yes! Great. I had an older version of GH installed where that option was permanently grayed out, so I never quite understood what it was supposed to do.

2) Well, I work with mechanical design, mostly light vehicles such as bicycles and variations thereof. Although frame design is mostly of a structural nature, there are a number of elements that interact mechanically. Also, as you may be aware, bicycle and high grade tubing is not of constant section so shelling method in FEA is out of the question, but even so, because the joint needs to be modeled very accurately, that means different geometry and properties for welded area, heat affected area and base material; like so a simpler FEA package may not suffice.

I don't know karamba extensively, rather superficially, actually, but I'm under the impression it mostly deals with beam analysis. Pls correct me if I am under the wrong impression. I must say it would be very nice to have a complete FEA package inside GH really!!

Typical workflow for me would be to model everything in Solidworks, and then export to Ansys Mechanical. Although Ansys needs to read every input and naturally remesh back again, integration within Solidworks, Catia, Inventor, Creo, Solidthinking... and the sort, works reasonably well.

Now, I don't remember Ansys having a Rhinoceros plugin so that you could bridge the 2 together, but maybe I should go check again.

3) Great work with that fractal tree. It's nice to know it is a possibility at least. I have tried Apophysis and others, but to my knowledge there's not an application that could deliver 3D fractal designs in a way that you could further manipulate with conventional modelling techniques, maybe apply textures and render, or export to CAM, 3D printing... etc.

P.S.: I have tried all the apps mentioned above and then some more. All of them have serious limitations when it comes to parametric design. For complex models they crash plenty upon rebuilding... a number of time consuming errors appear, and general work flow isn't very efficient for purely parametric work. Speaking for myself, I'd rather spend the time on a definition that enables me to have full control and then generate a new result within seconds, than model everything very quickly and then taking a long time with each new result.

(Thanks for the replies and sorry for the long text, you asked to elaborate).

I think you're coming to GH at a great time, for a number of reasons. A big one that comes to mind (considering your background) is that Daniel Piker is on the cusp of a new release of his Kangaroo plug-in. For years it's been an integrator-based physics engine, but he's reworked it to operate as a constraint-based solver that can operate as a very lightweight tool for mechanical systems (and for which one can write their own custom constraints using .NET) . I can imagine it becoming a very useful addition to your kit and workflow (if you haven't seen, here's a recent example: http://www.grasshopper3d.com/video/assembly-simulation-setup-kangaroo).

Hmm ... Aristo (is this a Greek name?: from Aristoteles/Aristotle)

We have some stuff in common although I operate a practice providing mostly architectural/object design discipline services (i.e no structural, HVAC etc). A small department does "pre" check/"interface" work as regards other disciplines (structural, HVAC, you name it et all). When possible "I force" other collaborating - also vertical - practices to work with Bentley Systems equivalent vertical products (for more than obvious compatibility/interoperability matters) On the other hand contemporary designs these days ... well ... you know ... more and more MCAD apps are used for designing parts (and/or the whole in some occasions).

My core AEC BIM product is AECOSim (+ Generative Components + GH in some occasions) and my core MCAD app is Siemens/NX (+ FEA/FIM/etc mostly used for designing building components and/or custom objects). CATIA is my favored personal toy even for "strict" AEC matters so to speak (you wouldn't believe what the next CATIA does). 

Creo: ex OneSpace ex SolidDesigner ex... ex ... ME30/10 [that was a stunning internal H/P product, many many years ago, when H/P was the real McCoy] is used rarely ... just to remember the good old days, he he.

And after the handshaking ... back to topic:

Your goal is to use GH as auxiliary app: a parametric (and maybe algorithmic) editor in order to  provide topological input to Solidworks right? This is not that simple (not because GH lacks the capability to outline some topology but due to assembly/component issues when that something is a hierarchy of objects: nested blocks in Rhino speech). I could elaborate further on that matter ... but this is not the place nor the time.

And your goal is also to "stay" within GH as "long as possible" by validating your topology (FEA/FIM and the likes) right? In order to feed SW with some "doable" thing right?

If all the above are true ... then your main issues are related with the nature of the output: so describe what you imagine best as workflow IF combos of "related" objects are in the pipeline (a void node has this as assembly that has these as parts that have these as assemblies that ... blah, blah).

On the other hand ... well ... Rhino is NOT a solid modeller (nor has any feature driven capability) as thus ... by what real-life means you think that you could/should use GH to do a structurally "validated" parametric thing like this? To do what exactly?

more soon, best, Peter

BTW: What fractals have do do with your design(s)? Or you are after a WOW full carbon bicycle that has a frame that looks like a fractal(C)(tm) spaghetti?.

Or you just fancy that kind of stuff? (it's kinda fun - up to a point - I admit).

he he

He he! a carbon bike with a fractal frame would certainly create a buzz in the industry! When I asked about fractals it was unrelated curiosity; maybe I just assumed it would be a natural strength of GH since any fractal generator is in essence parametric. Anyway since you mentioned it, I do try to put out different frame designs. Some more outrageous than others.

Frame design is actually quite interesting and challenging... a lot of tweaking is necessary and this is where GH shines. I can change any parameter on the fly and see all the implications it will produce in real time.

Back to the topic, you grazed my general idea. Component interaction in assemblies is sometimes modeled but it's not the bulk of the work. That would be the generation of topology and FEA validation. For topology GH is outstanding, but for FEA something like ANSYS is mandatory. Solidworks is, imo, great for 2D sketching and assemblies but for modeling (let alone parametric) and analysis is a bit frustrating making me waste a lot of time.

For simpler models and problems the workflow between Solidworks and Cosmos/Simulation is great, you get the feedback from Cosmos/Simulation and soon enough you have changed the model. I suppose Catia/Abaqus would perhaps feel the same. So my general idea would be to approximate this workflow without loosing the advantages of working in GH for topology generation.

Solidthinking has an interesting approach by means of pre-optimization, not really useful in my case, but it has the potential to save a lot of time where it applies.

For now I guess I'll have to try and expedite the process of using Rhino/GH-ANSYS back and forth. Any ideas?

By the way, not greek, although it was a very educated guess. "aristo" is portuguese for "protractor square", "compasso" well... you got it. This is a pseudonym I have used since the dawn of the internet, it sounds like a real name, but my real name is in fact Augusto, pleased to meet you all.

Hmm ... Augusto, here's my offer of the day:

Send some stuff over there (some abstract carbon fractal thingy what else? he he) and I'll try to "emulate" a variety of approaches (in the Name Of Science, he he) using  all things/apps available already mentioned (and some in smoke/pre beta phase). Then I'll report back what is my suggestion (or not). Since Dassault owns SolidWorks exporting from CATIA wouldn't be an issue (NX is bad on that matter, mind).

PS: I also designed a bike recently but that idiot client refused to pay me and initiated some legal actions as well (but what amateurs know about high class design?) :

best, Peter

PS: Assume that you do this (this was the first idea for the bike job mentioned above but I rejected it: too ordinary, let's do some next century stuff, he he):

I mean: this begs for feature driven design (aka history modeling: the PlanB in NX that can operate in Creo "mode" as well).

So the obvious question(s) are: IF (and I say it again: IF) we forget that polysurface "little" thingy (meshes are out of the equation for more than obvious reasons) where parametric "generic topology" ends and feature driven component design starts? And IF (and I say it again: IF) GH does something (whatever that something may be, FEA/FIM "validated" or not ) by what means SW could receive things (what things exactly?) in order to do what SW does? And if a history driven "combo" is required ... I mean ... well ... you know what I mean, don't you?

These are the 1B questions, he he

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