Arc by Center, Normal, Radius clarification


I’m trying to draw an arc on a surface and I’m confused by the Arc by Center, Normal, Radius node; there is no normal input, so I assume it gets bundled with the center input somehow: for the center input, the tooltip says “XYZ or Coordinate System”–but I have not been able to discover what a Coordinate System is.

I’ve tried feeding it a plane (nothing), a [point,normal] pair in a list (draws an arc, but doesn’t use the normal), and a [normal, point] pair (same results).

Any explanation would be appreciated . . .


Hi Andrew,

What version are you using? I don’t think that either 0.6.3 or 0.7.0 have an “Arc by Center Normal, Radius” node, although the functionality is there in both.

In 0.6.3, you can make an arc by various means, then use a Transform Curve node to move it to the appropriate place.

In 0.7, there is an Arc.ByCenterPointRadiusAngle with a “normal” parameter that I thing is more what you are looking for.