meter vs millimeter

I wan't to have my design model in mm and structural model in meters in the same GH file.

So does the scale set in the rhino file affect the accuracy of the calculations? i.e my design model is 4000mm wide but by structural stick model is linked with all the parameters scaled down by 1000 so its only 4mm in rhino space.

I'm assuming its all OK as karamba will just assume the 4mm is unitless so it is accepted as 4 meters.

Further to this are there any tolerance issues too? i/e when working in mm the tolerance is .01, that's fine in mm but scary when working in meters. Not sure if GH uses the rhino files tolerance for doing it's calcs.

Replies to This Discussion

Permalink Reply by Karamba3D on January 23, 2018 at 12:57pm

Dear Tim,

the unit setting in Rhino does not affect Karamba since all geometric input is interpreted to be in meters.

You can use different units as long as they are consistent.

When changing the units you will have to adapt the following:

The Assemble-, LineToBeam- and MeshToShell-components have an input plug 'LDist' which sets the minimum distance between two nodes to 5mm by default.
The 'MeshBReps' component of Karamba 1.2.2 does not work properly for meshes with an edge length smaller than 5mm.
In the ModelView-component the default length of segments for displaying beam meshes is 1m.
There might be problems with the line results on shells: you will have to increase the segment length there.

The solver though should work fine with the different number ranges.

Best,

Clemens

Permalink Reply by tim sullivan on January 23, 2018 at 9:15pm