>>First of all I understand that an Interpolate spline will be converted to >>control splines, I know that gives some users problems, but it is an >>action taken by other CAD system I use and is usually made directly >>after construction.

Steve,

Our interpolate spline will stay as an interpolate until you perform a relimit type operation on the curve such as trim/break/corner/chamfer. In that case it will be converted to a control polygon spline (ACIS always creates a control point spline as a result these operations and does not have a utility to convert a given control point back to interpolate). You can modify point, add/remove and it stays as an interpolate. An interpolate and control point spline have the same underlying NURB definition, just different way for the user to interface to the curve.


>>That after the change to control point, the spline is converted yet again >>to Interpolate when actions such as split are made. This does in VC cause >>problems with loss of endpoint continuity that was originally in place.

Would you have a specific example/file I could look at? That sounds like an error on my part and not ACIS.

Thanks,

Tim