Splines in SolidWorks 2007 has received some significant enhancements. There is added functionality as well as changes to existing features that make splines easier to use and control.

Let’s start with the changes to the spline handles. First and foremost, splines can now be adjusted asymmetrically as well as symmetrically. Instead of one “Tangent Magnitude” parameter for handle weighting in the Property Manager, there are now two “Tangent Weighting” parameters present (one for each direction). Handles are adjusted asymmetrically by default meaning that each side’s magnitude is independent of the other when the handle is “dragged” on the screen. If you desire to symmetrically adjust the weighting, hold down the ALT key and drag one side of the handle and the other side adjusts an equal amount.

Speaking of dragging, each handle now has two additional nodes on each side. The rotate and weighting adjustments now have separate nodes. The rotation adjustment is represented by a diamond shaped node. The magnitude or weighting adjustment is represented by the arrow at the end of each side of the handle. At the end of each handle is a circle shaped node. Dragging this node will result in both weighting and rotational changes (the default behavior in SolidWorks 2006). To me, this is a welcome change. With previous versions of SolidWorks, I can’t tell you how many times I have attempted to adjust only the weight on the screen and unwillingly ended up adjusting the angle of the handle as well. This change should allow the user to work in the graphics area more without having to tweak the parameters in the Property Manager to make slight changes.

Control Polygons have seen some enhancements as well. To start with, the control polygons are much more visible when active as compared to previous versions. Once the control polygon is activated, a triangle appears around each adjustment point.

Two Point splines have some added features that will surely come in handy with those of use doing Industrial Design work. First off, you can drag the control polygons of a two point spline and it DOESN’T result in the endpoints of the spline changing position! (Thank you SolidWorks!) This enhancement alone results in easier and faster manipulation. In addition, if a two point spline has equal curvature constraints on each end to surrounding geometry, a “Raised degree” option appears in the Property Manager (and is checked by default) that results in a high order C3 or better continuity for the spline.

I must say that SolidWorks has come a LONG way over the past three releases with the enhancements to splines. After using splines in SolidWorks 2007 for a few hours, the new functionality is missed greatly when switching back to SolidWorks 2006. To me that is always a good indicator of how well new functionality is developed and implemented. If you use splines from time to time, I highly recommend you check out splines in SolidWorks 2007 for yourself.