Working with Kangaroo, in mm

Hello everyone,

I need to use Kangaroo for a project and I want to work on a rhino file with millimeters as unit.
This means that my mesh is around 5000x5000 mm big, so 5x5 meters.

Then I don't know which unit I can set to put pressure and gravity on my mesh for example.

Does someone knows around which values I should play? Or is this possible anyway?

I hope I was clear enough.

Best

Roger

Replies to This Discussion

Permalink Reply by Hannes Löschke on May 3, 2014 at 6:46am

Kangaroo expects everything in m. No way to change that.

You can either set Rhino units to Meters and let it scale appropriately. Make sure to scale tolerance as well.

Or you can scale any numeric constant or input for Kangaroo that relates to length... that might lead to errors quickly.

Permalink Reply by Daniel Piker on May 3, 2014 at 7:07am

This is incorrect - Hannes, I do appreciate your effort to answer questions, but I've corrected this same point before, please don't repeat misinformation.

All that really matters is that your units are consistent. However, using meters/kilograms/pascals/seconds does make things simpler, and are generally what I recommend. For something 5 meters across I would certainly say that working in meters is easiest, and it should be possible to have the tolerance you need for any practical purpose.

However, since the units are defined relative to each other, if you really need to work in mm, you can change the other units used appropriately. So in this case mm, grams and millinewtons.

Permalink Reply by Hannes Löschke on May 4, 2014 at 12:44am

I believe we are on the same page here. While being imprecise and very short, I don't think my answer is incorrect. I should take more time to answer stuff like that. :) Please read my three paragraphs as follows:

Kangaroo is based on the assumption and recommendation of meters as Rhino units. That means any preset value in a Kangaroo component you drop to the canvas will default to values assuming meters as a base. Basically any available tutorial and documentation is based on that. Kangaroo is not aware of any unit setting you do in Rhino and there is no global switch to tell Kangaroo to use millimeters as a base unit.

The most straight forward way is to cope with that is to just switch to Meters in Rhino. If you adjust the tolerances accordingly, this will have no effect on Rhinos modelling behavior. The only difference is your area, volume and length readouts, as well as dimension will be meter based.

You can also change the base unit for Kangaroo to mm, if you need to. You will have to adjust any preset that Kangaroo provides. While certainly possible, you need to adjust every constant by hand and repeat for any new component you add. It is also very easy to confuse all the other physical units involved in calculating the preset values, so my personal recommendation would be to stay away from that, if you can.

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