Super quick intro. I am making a terrain generator (With a MC exporter mostly to debug). For the islands I am creating a map with points, and create a Voronoi diagram from it. Each intersection (Where lines of the shapes meet) has a different height, depending on the distance to the coast. The coast itself is elevation=0. Here you can see what I meant. Where the wite lines meet is an intersection. Each one of the holds a different value.

However, whatever I try, I keep getting weird heightmaps. (I can't link more than two images, so I will explain). You can clearly see the difference between each site, yet they are slightly sloped.

In-game this looks like this: enter image description here

The red blocks that stick out is the height of the intersection. Sites are created by references to the intersections, since they have IDs.

The code I am using at the moment:

Point p = new Point(x, 1, z);

        double[] distances = new double[points.length];
        double[] percentages = new double[points.length];
        double[] elevations = new double[points.length];

        int max = 0;
        for(int i=0; i<points.length; i++)
            if(parent.getIntersections().fromIndex(points[i]).getElevation() > max)
                max = (int)parent.getIntersections().fromIndex(points[i]).getElevation();

        double totaldist = 0;
        for(int i=0; i<points.length; i++) {
            distances[i] = parent.getIntersections().fromIndex(points[i]).getLocation().surfaceDist(p);

        for(int i=0; i<points.length; i++){
            percentages[i] = (distances[i] / totaldist);

        for(int i=0; i<points.length; i++)
            elevations[i] = (percentages[i] * (parent.getIntersections().fromIndex(points[i]).getElevation()));

        double heightTemp = 0;
        for(int i=0; i<elevations.length; i++)
            heightTemp += elevations[i];
        heightTemp = max-heightTemp+max;

        int height = (int) heightTemp - 3 + parent.getConfig().getSeaLevel() ;
        height = (height>255 ? 255 : height);

The code's quite weird and unorganized since I pretty much tried anything I could come up with. "points" is an array containing the reference IDs to the correct intersections "parent.getIntersections().fromIndex(int index)" is the way to retrieve an intersection from the index/reference id. "p" is the point to get the altitude/elevation from. "Intersection.getElevation()" returns the elevation (Anything above sea level).

Sorry if this is real vague, I have no clue on how to explain this properly.

  • \$\begingroup\$ Looking at this makes me really wish I understood voronoi \$\endgroup\$
    – Shaun Wild
    May 27, 2016 at 10:19
  • \$\begingroup\$ @ShaunWild It's not that complicated to understand, generating a diagram can also be done using some APIs! I started this project a few weeks ago, and did tons and tons of background reading. Go for it! \$\endgroup\$
    – Daniël V
    May 27, 2016 at 10:55

1 Answer 1



After thinking this through almost a complete day (I encountered the problem yesterday), I realized I had the function to determine the height of any given point using the distance to the ocean. Why would I need to take averages and complicated calculations if I could just check the distance to the nearest coast, and then use the formula?


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