How can I add a RADIAL dimension?

Rhino Developer
1

I am trying to add a radial dimension via Python/RhinoCommon:

            dimension = Rhino.Geometry.RadialDimension(pCenter, pTip, vX, vZ, dOffset)
            id = doc.Objects.AddRadialDimension(dimension)

This works fine, but I (always) get a DIAMETER dimension instead of a RADIUS dimension. The property IsDiameterDimension is read only, so how can I define the type?

2

Hi fabian,

Can you make use of a user option via CommandLine (Radius or not Radius), like so? :

params = ("Radius", "No", "Yes")
isRadius = rs.GetBoolean("Radius", params, (False) )

dimension = Rhino.Geometry.RadialDimension(pCenter, ...
if isRadius[0]:
    dimension = dimension / 2
id = doc.Objects.AddRadialDimension(dimension)

// Rolf

3

@fabian,

not sure where to change the type but if you do not need a dynamic dimension you might try this ugly hack before adding it to the document:

dimension = Rhino.Geometry.RadialDimension(pCenter, pTip, vX, vZ, dOffset)
dimension.Text = "R{}".format(dimension.NumericValue*0.5) 
id = doc.Objects.AddRadialDimension(dimension)

Note that IsDiameterDimension still returns True, would be to easy, also tried to change diameter.Text to “R<>” but it remains a diameter dimension and that does not change the value, just the prefix…

c.

4

Hi Rolf,

I don’t think this is gonna work, since dimension is created as an instance of Rhino.Geometry.RadialDimension. You can’t divide that by two and if you assign a float value to it AddRadialDimension won’t accept it as input anymore.

Using a command script would be the last resort of course, but if there’s a way to avoid this I’d rather go for “proper” programming…

Thanks anyway!
Fabian

5

Hi clement,

thanks for the idea. Since the resulting model is to be exported as fabrication data both in Rhino and DWG-Format for a client, I’d rather have proper dynamic dimensions in there. But for printing PDFs I’ll just change the text.

Do you happen to have any idea how the TextFormula-property of the AnnotationBase-class is working?
The documentation is a bit minimalistic at this point…

Best, Fabian

6

Hi Fabian,

The TextFormula basically determines the format of the Text property. Use the angle brackets <> to determine the position of the NumericValue property.
For example the following dimension.TextFormula:

dimension.TextFormula = "Ø _something in here <>"

Will result in the the following dimension.Text:

"Ø _something in here 50"

(in case your NumericValue is 50)

Also if you are using the Ø character, make sure that you add the # coding=utf-8 on top of your script.

7

@djordje, @fabian,

i am not entirely sure if TextFormula is properly evaluated when used in a radial dimension. I thought that these only apply to Text fields, as described in the Rhino helpfile under “Text fields”. Eg if i try this on a circle with diameter 20:

radial_dimension.TextFormula = "Ø<> %<modelunits>%"

or this:

radial_dimension.Text = "Ø<> %<modelunits>%"

If just creates the radial dimension with this dimension text: Ø20 %<modelunits>%

The angle brackets can be used in the Text property too eg. using dimension.Text = "R<>" but as described in my first reply it still printed a diameter value instead of the radius.

If the dimension needs to stay dynamic, i’ve wondered if you couldn’t create a seperate dimension style with LengthFactor set to 0.5 and assign that after replacing the diameter symbol with R ? But i’d rather choose the static way and force the correct radius value to prevent errors in the downstream…

Maybe @dale can take a look why IsDiameterDimension is read only or has a fix for the problem ?

c.

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