galapagos

Hi there,

I'm relatively new to grasshopper and want to know how to use the galapagos function in order to generate a form (lofted surface) comprising of different surfaces that are optimised for maximal exposure of those surfaces to the sun. I'm guessing that the genome would refer to the parameters controlling the number and angle of surfaces that make up the form and the fitness would refer to 'maximum exposure to the sun'.

Replies to This Discussion

Permalink Reply by David Rutten on May 18, 2013 at 2:48am

Hi Melanie,

Galapagos is -at least in theory- capable of doing this, but you may run into practical limitations. First of all you need to define your shapes in such a way that all free variables are either linked to Number Sliders or Gene Pool objects. Galapagos can only operate on these two objects.

You mentioned you're lofting your surface, which is not immediately accessible to Galapagos as a Loft operates on a set of curves. Now these curves may have control-points whose x,y,z coordinates could be associated with sliders or genepools, but you need to tell us how your shapes are defined.

Lastly, Grasshopper does not provide sun-exposure analysis by itself. For that you will need either a 3rd party plug-in or you'll need to develop that from scratch.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Melanie Modafferi on May 24, 2013 at 7:41am

Thanks David,

I've found that it's quite hard to define what is fit in most situations. Perhaps in the future there could be some sort of component that makes it easier for non-programmers to define this.

Permalink Reply by David Rutten on May 24, 2013 at 12:08pm

This is not really possible. Someone has to define fitness and the only person capable of doing this is the person who understands the problem. The software certainly doesn't understand the problem so it will never be able to invent a fitness function.

If you can write down (in English) how you would evaluate two competing states in order to pick the better one, we may be able to help you convert it into a Grasshopper algorithm.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Melanie Modafferi on May 24, 2013 at 9:40pm

Yes this is true, I guess what's required is just a deeper understanding of my problem. If I was to break this down, I'd say that the two competing states are 1. optimal angles of surfaces and 2. maximum exposure of these surfaces to the sun. I think the confusion lies in the fact that the sun is not static, so how a form with static surfaces can be generated is beyond me.

Permalink Reply by David Rutten on May 25, 2013 at 4:59am

...the sun is not static, so how a form with static surfaces can be generated is beyond me.

I assume the purpose of this facade is to minimize some sort of cost (cooling, heating, lighting?). So even though the sun is moving throughout the day and throughout the year, there will still be a specific orientation that results in minimum or maximum exposure. To do it really right you'll have to take all possible suns into account. This even includes weather data as the sun in winter may be both weaker because it's lower but perhaps winter tends to have clear skies whereas summers may be cloudy in your particular location.

It's a complicated problem that involves a lot of data and computation.

David Rutten

david@mcneel.com

Poprad, Slovakia

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