In a typical freeform surfacing process, CAM software generates piecewise linear toolpaths. In this case, marks may appear on the machined surfaces due to the non-smooth planning of the feedrate during interpolation.

B-Spline interpolation with a given degree and controlled weights at each point of the trajectory, implemented in the ViS CNC system, allows you to smooth the tool path with a given accuracy.

Spline interpolation works especially well in the case of simultaneous processing along 3 axes. Below you can see three screenshots: the first is a toolpath without smoothing, that is, this was the toolpath at the output of the CAM program. The second - with spline interpolation enabled and degree 1. The third - with spline interpolation enabled and degree 3.


Obviously, the smoother the tool trajectory, the less acceleration-deceleration sections there will be and the less time it will take to process. And this, in turn, directly affects the quality of the treated surface.


Parameters that set and affect various characteristics of the spline curve: 3300, 3301, 3302, 3303, 3304.
Parameter 3300 - global enable/disable spline interpolation. In the control program (G-code), spline interpolation is activated with G code G64 and deactivated with G61;
Parameter 3301 - smoothing mode: #1 - the angle between the segments is less than the threshold angle, #2 - the angle between the segments is greater than the threshold angle.
Parameter 3302 - the threshold angle between path segments when spline interpolation becomes active.
Parameter 3303 - degree. Specifies the degree of "involvement" of neighboring segments.
Parameter 3304 - smoothness. The larger this parameter, the smoother the trajectory becomes.