Error Message using Arc by Center, Radius, Parameters Node


I went to a day long workshop held by Autodesk on Dynamo, and after returning back to the project I am working on I ran into some errors that I can’t seem to solve in Dynamo. Maybe there is a simple solution that I just am unaware of since I am a fairly new user.

The end goal is to create a parametric column that blends from one shape to another. I am running into an error using the Arc by Center, Radius, Parameters node. The arror that I receive is:

Unable to cast object of type ‘Container’ to type ‘Number’.

I’m not really sure what is wrong since I have Start, End, and Center points along with a radius. Making an arc seems to be a pretty simple task in theory.

I’m also wondering if there is anyway to do a square root (?<i>a) </i>formula? It is the only break in my file at this point assuming my previous issue gets fixed.

Thanks for any help you can give.

Script_Forum Help

Hi Seth – so glad you’re trying this out!

To answer your first question, it looks from the picture like you are trying to pass XYZs to the start and end parameters. The “start” and “end” inputs are for numbers, from 0 to 2pi along the arc.

To use XYZ rather than parameters, you are probably looking for “Arc By Start, Middle, End”

For a square root, type in the formula node sqrt(x). You’ll find other functions too at (There’s a dedicated square root node in the daily build version, so it’s on it’s way.)