Tangent arc in sketch using the Fusion 360 API?

[doge0161]

Hello!

I am trying to create a tangent arc in a sketch using the Fusion 360 API in Python. I have found the addByThreePoints and addByCentreStartSweep methods, but there does not appear to be a tangent arc method.

I have scoured both the Fusion 360 Object Model PDF and the internet, and I cannot find whether the tangent arc command is exposed through the API or not.

If not, could you please provide me with some guidance on how to create a tangent arc using text commands? Using @kandennti's helpful guide (found here: https://forums.autodesk.com/t5/fusion-360-api-and-scripts/use-textcommands/m-p/9645717#M10758), I retrieved the ID of the tangent arc command (ArcTangent), but I am unsure where to go from here.

Thank you for the help in advance.

[BrianEkins · Accepted solution]

You don't create an arc that is tangent, but instead, you add a tangent constraint to the arc and the geometry it's supposed to be tangent to. It's best to initially draw the arc so it is close to geometrically tangent so when you add the constraint you don't get a big shift. Look for the geometricConstraints property on the sketch, which will return a GeometricConstraints object that supports many methods for creating different types of constraints.

[doge0161]

I figured this might have been the case. Thank you for the help, Brian.