jonghough / kurvz

Unity Kurvz, Splines and Voronoi scripts

kurvz

Scripts for using cubic splines and bezier curves

What is this?

Some scripts for moving objects smoothly between any points in 3-space. For example, if I want an objec tto move at a steady speed between points (0,0,0), (10,-10, 10), (20, 0, 300), (15, 100, -100) , then I can use the CatmullRomSpline class to do this. The object does not move in as traight line between the points and make a sharp turn to get to the next point, like a waypoint system. The object follows a nice, smooth curve.

Example

I want my object to travel between (Vector3) points p1,p2,p3,p4,p5 on a smooth curve, at speed 10 units/sec. First we have to wrap Vector3 in a SplineVector interface (not only Vector3, any type will do, it just needs to return a Vector3 when asked.

_mySpline = new CatmullRomSpline(mySplineVectorList, onFinishCallback);

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//and in the update

this.transform.position = _mySpline.UpdateAtSpeed(Time.deltaTime, 10);

That's it.

You can also add new points to the CatmullRomSpline so the object can move forever, because it will have new points to travel to. (Points already visited are removed).

see SphereBehaviour.cs for a working example.

Voronoi Diagram

We can create a Voronoi Diagram for a set of points using the VoronoiGenerator class. For example, look at the following gif

This shows the SceneView of a 10 points, which move randomly every frame. The voronoi diagram, shown by the lines, (Debug.DrawLine()) is calcualted each frame. (The per-frame calculation is a little bit heavy)

How to use

The VoronoiGenerator will only accept VectorNode objects, so you can wrap Vector2 in one of these (Vornoi Diagrams are 2D, so don't try to use Vector3).

VoronoiGenerator vornoiGen = new VoronoiGenerator(myListOfVectorNodes);
voronoiGen.CreateDiagram();

THis will creat ethe list of points and edges that can be used to construct the voronoi diagram. The diagram can be updated by calling voronoiGen.Rebuild(); This will recalculate all data for myListOfVectorNodes, so if the (x,y) coordinates have changed, then the vornoi diagram will also change.

100-Point Voronoi

Example of voronoi diagram for 100 points (not recalculated every frame because it would be too heavy)