help first loop_distance Brep Cp

Dear all,

i attempt to design my first loop in grasshopper through this amazing plug-in.

I want to test the distance of four vertices of a surface modeled in rhino and a cylinder that change position on the upper edge in according to the point on that.

my loop should be like

if distance<constrain return a value true, otherwise move the point on edge and recalculate the condition .

the constrain is a value i have chosen.

The first big issue is that to move the point on the edge to design the cylinder i have used a normal slider and it's impossible (for me ) figure out to link in input a flow.

Anyway i will grateful if somebody can give some advices .

Thanks in advance

Darioscreenshot.jpg

Replies to This Discussion

Permalink Reply by Yannis on November 13, 2011 at 4:21am

Hi Dario,

It seems a bit difficult to grasp what it is about. Would it be possible to share the definition maybe? Still, it seems that you are trying to tackle a simple distance minimization problem, so in this case I would suggest to also take a look at Galapagos, it does a nice job at optimizing simple single-objective problems.

Permalink Reply by Dario on November 13, 2011 at 6:22am

Hi Yiannis,

yes sure i attached my definition.

How you can see i tried also with galapagos , but it is very hard add a constraint to a flexible solver.

Basically, if i think to my target is easy, but i have found some difficut problems to implement the end part of the definition.

The condition that i have used as last option to define the fitness parameter is

If(distance < constraint, 1000000, Sqrt(distance))...without a great succes

If you could help or adjust this short part, i will appreciate so much your help.

thanks in advance

dario

Attachments:

definition.gh, 19 KB
surface.3dm, 244 KB

Permalink Reply by Yannis on November 21, 2011 at 2:30pm

Hi dario,

I've modified your file to use galapagos to solve the constraint satisfaction problem that you seem to have. Just open galapagos and start.

Actually it doesn't perform very well, and the overall solution quality seems to degrade over time (could this be an issue with the GA specific to Galapagos?).

The problem seems to be quite constraint, so maybe through your cylinder definition you could "ease up" on the constraints a little bit.

Hope that helps.

Yiannis

Attachments: