Spheres, Hollow Sphers, Circles, Hollow Circles Tutorial

Hello,

I had some serious problems when coding my plugin because I didn't have a clue how to make hollow spheres or circles but I have a method that works amazingly.

Here is my code to make a set of locations hollow

Code:java

private Set<Location> makeHollow(Set<Location> blocks, boolean sphere){
        Set<Location> edge = new HashSet<Location>();
        if(!sphere){
            for(Location l : blocks){
                World w = l.getWorld();
                int X = l.getBlockX();
                int Y = l.getBlockY();
                int Z = l.getBlockZ();
                Location front = new Location(w, X + 1, Y, Z);
                Location back = new Location(w, X - 1, Y, Z);
                Location left = new Location(w, X, Y, Z + 1);
                Location right = new Location(w, X, Y, Z - 1);
                if(!(blocks.contains(front) && blocks.contains(back) && blocks.contains(left) && blocks.contains(right))){
                    edge.add(l);
                }
            }
            return edge;
        } else {
            for(Location l : blocks){
                World w = l.getWorld();
                int X = l.getBlockX();
                int Y = l.getBlockY();
                int Z = l.getBlockZ();
                Location front = new Location(w, X + 1, Y, Z);
                Location back = new Location(w, X - 1, Y, Z);
                Location left = new Location(w, X, Y, Z + 1);
                Location right = new Location(w, X, Y, Z - 1);
                Location top = new Location(w, X, Y + 1, Z);
                Location bottom = new Location(w, X, Y - 1, Z);
                if(!(blocks.contains(front) && blocks.contains(back) && blocks.contains(left) && blocks.contains(right) && blocks.contains(top) && blocks.contains(bottom))){
                    edge.add(l);
                }
            }
            return edge;
        }
    }

Here is my code to make a cylinder, hollow or not

Code:java

public Set<Location> circle(Location location, int radius, boolean hollow){
        Set<Location> blocks = new HashSet<Location>();
        World world = location.getWorld();
        int X = location.getBlockX();
        int Y = location.getBlockY();
        int Z = location.getBlockZ();
        int radiusSquared = radius * radius;
 
        if(hollow){
            for (int x = X - radius; x <= X + radius; x++) {
                for (int z = Z - radius; z <= Z + radius; z++) {
                    if ((X - x) * (X - x) + (Z - z) * (Z - z) <= radiusSquared) {
                        Location block = new Location(world, x, Y, z);
                        blocks.add(block);
                    }
                }
            }
            return makeHollow(blocks, false);
        } else {
            for (int x = X - radius; x <= X + radius; x++) {
                for (int z = Z - radius; z <= Z + radius; z++) {
                    if ((X - x) * (X - x) + (Z - z) * (Z - z) <= radiusSquared) {
                        Location block = new Location(world, x, Y, z);
                        blocks.add(block);
                    }
                }
            }
            return blocks;
        }
    }

and here is my code for a sphere

Code:java

public Set<Location> sphere(Location location, int radius, boolean hollow){
        Set<Location> blocks = new HashSet<Location>();
        World world = location.getWorld();
        int X = location.getBlockX();
        int Y = location.getBlockY();
        int Z = location.getBlockZ();
        int radiusSquared = radius * radius;
 
        if(hollow){
            for (int x = X - radius; x <= X + radius; x++) {
                for (int y = Y - radius; y <= Y + radius; y++) {
                    for (int z = Z - radius; z <= Z + radius; z++) {
                        if ((X - x) * (X - x) + (Y - y) * (Y - y) + (Z - z) * (Z - z) <= radiusSquared) {
                            Location block = new Location(world, x, y, z);
                            blocks.add(block);
                        }
                    }
                }
            }
            return makeHollow(blocks, true);
        } else {
            for (int x = X - radius; x <= X + radius; x++) {
                for (int y = Y - radius; y <= Y + radius; y++) {
                    for (int z = Z - radius; z <= Z + radius; z++) {
                        if ((X - x) * (X - x) + (Y - y) * (Y - y) + (Z - z) * (Z - z) <= radiusSquared) {
                            Location block = new Location(world, x, y, z);
                            blocks.add(block);
                        }
                    }
                }
            }
            return blocks;
        }
    }

How this code works is, it creates a list of all the blocks that need something done to.

You can use the code like this

Code:java

for(Location location : sphere(player.getLocation(), 7, true)){
    location.getBlock().setType(Material.GOLD_BLOCK);
}

The following code would make a sphere 7 big which is hollow around the player Hope my code helps you out and if anyone can find a way to improve my code that would be very handy

 

Jack Price-Burns I think this lib would help you out: http://dev.bukkit.org/bukkit-plugins/effectlib/

 

Jack Price-Burns First of all, I recommend you to stop location.add(x,y,z) and use vector's instead( this is just my thing but it always worked perfectly), second to make a sphere hollow you can add this if((loc.distance(middle)<radius+1)&&(loc.distance(middle)>radius-1))

Marten Mooij That also works xD

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Marten Mooij that lib is amazing I will most definitily make use of this

Also thank you Marten Mooij nuno1212sss for the advice

 

Jack Price-Burns
A few optimization notes.

• When you define front, back, end, etc.. you could do l.add(1,0,0), l.add(-1,0,0), etc. This will shorten your code just a tad.
• In you makeHollow method, the two for loops are almost identical. You could condense your method easily by having one for loop with the if-then-else statement inside the loop.
• You might want to look into making this not use looping through x, y and z values. This can be server intensive if many objects or large ones are being generated. Other tutorials already feature this. I have heard that vector math is less intensive, but I could be wrong on that note (I've never tested it).

Otherwise, it's a decent tutorial, albeit there is no explanation at all for your code. The source alone is not a tutorial. You need to explain your steps and why you did what you did.

 

Jack Price-Burns Glad I could help out.

 

Calling it a tutorial and not even a single comment in your code.

 

Without Vector objects you could have less overhead caused by all object creation.

What exactly do you mean by vector math? I wonder about your solution to find all blocks on the 'edge' of the sphere.