Break At Point

[JKLINE]

I'm looking to break a line or arc at a point. I'm finding BreakManyPiecesParameters in the API but it's not showing how to use an actual point. Will I be better off deleting the original geometry and then creating two lines/two arcs?

Thanks,

Jeremy

[JKLINE]

I decided to use BreakAtMidpoint(arc).

The problem I'm currently having with it is that it breaks the arc at the midpoint, which is wonderful, but then one of those halves gets broken again.

I'm not seeing any error in my logic though. Does breaking an Entity store the two new pieces under the same EntityID?

            void breakArcsWithPoints(){
                foreach (var i in tempList3) {
                    var ArcID = Geometry.RetrieveEntity(i);
                    if (ArcID is ArcGeometry arc){
                        var arc1X1 = arc.EndPoint1.x; // Arc x 1
                        var arc1X2 = arc.EndPoint2.x; // Arc x 2
                        var arc1Y1 = arc.EndPoint1.y; // Arc y 1
                        var arc1Y2 = arc.EndPoint2.y; // Arc y 2
                        var arc1Center = arc.Data.CenterPoint;
                        Point3D arc1StartPoint = new Point3D(arc1X1, arc1Y1, 0.0);
                        Point3D arc1EndPoint = new Point3D(arc1X2, arc1Y2, 0.0);
                        var tolerance = 0.001;
                        foreach (var v in tempList4){
                            var u = PointGeometry.RetrieveEntity(v);
                            if (u is PointGeometry point) {
                                var ux = point.Data.x;
                                var uy = point.Data.y;
                                Point3D uPoint = new Point3D(uy, ux, 0.0);
                                var delta3Xneg = (arc1Center.x - uPoint.x);
                                var delta3Yneg = (arc1Center.y - uPoint.y);
                                var delta3Radneg = Math.Atan2(delta3Xneg, delta3Yneg);
                                var pt3degreeNeg = VectorManager.RadiansToDegrees(delta3Radneg);
                                if (pt3degreeNeg < 0.0){
                                    pt3degreeNeg = (pt3degreeNeg + 360);
                                }
                                var startToUDist = Math.Abs(VectorManager.Distance(arc1StartPoint, uPoint));
                                var endToUDist = Math.Abs(VectorManager.Distance(arc1EndPoint, uPoint));
                                if ((startToUDist >= (endToUDist - tolerance)) && (startToUDist <= (endToUDist + tolerance))){
                                    GeometryManipulationManager.BreakAtMidpoint(arc);
                                }
                            }
                        }
                    }
                }
            }

 

[crazy^millman]

The age old break an arc at 3 o'clock in Mastercam issue than no one is 20+ years has ever been able to explain. Good luck getting a solid answer on that one. I will be extremely surprised if anyone can come back and give us the mathematical reason for it.

[JKLINE]

If it's a bug, I'll actually move on. I can get the size of the arc, and if it's less than A and it's endpoint matches another arc that is also less than A, JoinEntities.

[JKLINE]

New Solution ::

 

                                    BreakManyPiecesParameters broken = new BreakManyPiecesParameters()
                                    {
                                        Curves = true,
                                        Number = 2,
                                        Method = 0
                                    };
                                    tempList7.Add(arc);
                                    GeometryManipulationManager.BreakManyPieces(tempList7,broken,ref tempList5,ref tempList6);

 

[Roger Martin from CNC Software]

Just curious to what result you were looking for.

You are breaking the entities into 2 pieces using BreakManyPieces, correct?

Quote

I'm looking to break a line or arc at a point. 

...at a point
Where is the "at point" in this?

[JKLINE]

I took 2 arcs

shifted 1 X+0.001 & Y+0.001
shifted the other X-0.001 & Y-0.001

I created points of where the two circles intersect

I then filtered to only keep the points that are actually on the arc

 

The goal here is to have a chain color A until it hits a point and then change to color B until it hits another point at which it turns back to color A

[JKLINE]

Roger,

To clarify, I tried the BreakAtMidpoint method but it gave me 3 arcs instead of 2 so I decided to try another method which seems to be working.