algorithmic modeling for Rhino


Long time Rhino user, but recent user of Grasshopper.  I have a basic question, but I have a feeling there isn't an easy solution.  I have a very complex ghx written for an architectural project that was using the metric system.  All of the sliders, and numbers are based off of meters.  I am trying to reconfigure this to use for an imperial project here in the US.  Everything is already set up for new users [slide this to increase "X" and slide this to increase "y" and so forth].  It was made so people like me didn't have to get in there and remake everything. 

Question is can I easily switch the units of the file so everything works in ft and in?  Changing the rhino units doesn't seem to effect the ghx.  I basically want the 1m to just work for 1ft, and then I can manually adjust the numbers up to account for the scaling issues.  Like I said the file is pretty dense, so there is basically no way for me to redesign it. 

Thanks for the help!

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Replies to This Discussion

Grasshopper is a unit-less application, as is Rhino in fact. Units are only little bits of text that are appended to numbers when these numbers are displayed to the user. Rhino doesn't care whether you work in feet, or meters, or parsecs, it will only affect the formatting of numerics.

When you switch unit systems in Rhino, you can ask for your geometry to be scaled so that the real dimensions remain unaffected. This is easy in Rhino because everything needs to be scaled. Doing this in Grasshopper will never work automatically, because Grasshopper deals with other data types in addition to geometry.

At present there is no mechanism whatsoever to scale geometry, values, sliders, text panels, digit scrollers, control knobs or any other kind of data from one unit system to another.


David Rutten

Poprad, Slovakia

This is what I thought.  I am trying to manually convert my new numbers into the metric system, but this might become to big of a hassle and not really a sustainable practice. 

for the record I hate feet and inches. 

maybe another option could be that you make make a cluster that is the conversion mathematics you require. Or if its simple for instance. (1 inches = 25.4 millimeters) then just save a multiplication component off to the side somewhere with 25.4 set as its B value, then just input this between your sliders / values and the component they connect to.


maybe use save state manager to switch between sliders set to inch size and sliders set to mm size.

I just tried this, and in a way it works.  It might be easier if I could get it to work this way instead [see image]. 

A is the distance in meters that I have converted to ft and inches [B].  Which works out only if you guess or calculate what the actual conversion is. 

Is there anyway that I can manipulate B so that it will change A.  Meaning I type in that i want something to be 38" and it will do the reverse and make it work in meters.  there are literally 50-60 of these situations set up so being able to manually change the numbers in imperial and not metric is ideal. 

do you mean like this?

please forgive my inability to explain myself clearly in a program I obviously have no idea in what I am doing...

That is just the reverse of what I had  ft to m instead of m to ft.  My sliders are already set up to work for m, thus I want a way to manipulate those numbers in imperial.  I want to type in [or adjust a slider in imperial], that somehow then changes the m slider. 

Me changing the number under my B, that flows back and changes A.

I see, well i think the only thing that can change a slider value (besides you) is Galapagos.

Hey Jeff,

That looks like my Arch Dim converter! Glad to see someone's getting some use out of it. 

I'll admit I'm still not sure exactly what you are after, but maybe this? (also see attached)

It's the reverse of the converter you posted, but you can actually enter feet, inches, and fractions of inches and it will be converted to decimal values for you. These decimal values will still be in feet and inches, so if you need to convert to meters you will have to do that conversion to the output.


Hi Brian, the Arch component that you posted here is exactly what I am looking for, only problem is when I open it in my GH 0.9.0006 it comes out labeled as OLD and it completely disregard the fraction denominator.

See attached image.

Any suggestion?



Hey Daniele,

I just took a quick look and there was a path mapper in there that didn't account for a certain branch structure. Try this and let me know if it works.



Sorry Brian, now it doesn't open at all.

It brings up a Message: Object reference not set to an instance of an object. 

Not sure about this. Thanks for your help.


might be a 9.0066 thing. Can you upgrade to 9.0014?






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