Unit comparison between Rhino <> Dynamo

[mostaphaRoudsari]

@ksobon looks like there is no check for units from the source document. It is probably a good idea to add one.

[mostaphaRoudsari]

@ksobon What do you think about adding units to each geometry before you pass it to Dynamo? You can read it back in Dynamo.

import scriptcontext as sc
x.SetUserString("units", sc.doc.ModelUnitSystem.ToString())

[ksobon]

yes, this sounds good. I will get that in there... thanks!

[ksobon]

Mhmmmm while reading Rhino (3dm) files I can just get ModelUnitsSystem from the file and pass it along from there to every geometry conversion node.

units = rhModel.Settings.ModelUnitSystem

create a conversion factor from there:

def toDSUnits(_units): 
if _units == rc.UnitSystem.Millimeters:
        return 0.001
    elif _units == rc.UnitSystem.Centimeters:
        return 0.01
    elif _units == rc.UnitSystem.Decimeters:
        return 0.1
    elif _units == rc.UnitSystem.Meters:
        return 1
    elif _units == rc.UnitSystem.Inches:
        return 0.0254
    elif _units == rc.UnitSystem.Feet:
        return 0.3048
    elif _units == rc.UnitSystem.Yards:
        return 0.9144

so this works for reading 3dm files. Reading a serialized GH file will require that I write that information to geometry. For that we can use UserStrings or since new Mantis Shrimp can send data I can just send over a simple data pocket with every export that will contain UnitsSystem name.

[ksobon]

OK, I just added units to DY>GH>DY transfers. For some reason it slowed down my graph execution in GH. I will test that further to make sure that it doesn't compromise speed too much. PS. On transfers between DY and GH i am assuming that DY side is always operating in Meters (DY uses meters internally) so I am only adjusting units to and from Meters.