[SOLVED]Is My Sphere Math Bad? - I Need a Fresh Pair of Eyes...

I'm trying to use sphere math to create a "circle" of fire, but for some reason I seem to be getting a quarter of a circle no matter how hard I try. As far as I can tell, my sphere math is perfectly fine, but apparently not. Perhaps a fresh pair of eyes can discern the potential problem:

Code:java

/*Checks if the block at blockLoc, in the world that player is in, is an air block, and if it is, sets that block to fire.*/
public static void ignite(Location blockLoc) {
 
    //Get the block at blockLoc.
    Block block = blockLoc.getWorld().getBlockAt(blockLoc);
 
    //If the block at blockLoc is air, set it to fire.
    if (block.getType() == Material.AIR) {
 
        block.setType(Material.FIRE);
    }
}
 
/*Calls the ignite(blockLoc, player) method on all points within a sphere of a radius represented by the double parameter "radius",
* and centered on the Location parameter "center" in the world that player is in.*/
public static void sphereBurn(Location center, double radius) {
 
    radius += 0.5;
    //Get the square of the radius.
    final double radSquare = square(radius);
 
    //Get the mathematical ceiling of radius.
    final int radCeil = (int) Math.ceil(radius);
 
    //Get the center's coords.
    final double centerX = center.getX();
    final double centerY = center.getY();
    final double centerZ = center.getZ();
 
    //Loop through all points inside of a sphere described by the given parameters.
    for(double x = centerX - radCeil; x <= centerX + radCeil; x++) {
 
        for(double y = centerY - radCeil; y <= centerY + radCeil; y++) {
 
            for(double z = centerZ - radCeil; z <= centerZ + radCeil; z++) {
 
                //Get the square of the distance between the sphere center and the current point.
                double distSquare = square(x - centerX) + square(y - centerY) + square(z - centerZ);
 
                //If the square of the distance to the current point is greater than the square of the radius, skip forward to the next point.
                if (distSquare > radSquare) {
 
                    continue;
                }
 
                Location currPoint = new Location(center.getWorld(), x, y, z);
 
                //Ignite the current point.
                ignite(currPoint);
            }
        }
    }
}

 

Code:

double distSquare = Math.sqrt(square(x - centerX) + square(y - centerY) + square(z - centerZ));

 

If you put the square root in there, it returns the distance, which is not what I want. I want the square of the distance (which the variable name implies) as I am comparing it to the square of the radius.

The idea being that if you loop through all the points in a cube of side length radius*2 that is centered on the point 'center', then all points in that cube that satisfy the condition (x - centerX)^2 + (y - CenterY)^2 + (z - centerZ)^2 <= radSquare will be on or inside of the desired sphere with a radius of 'radCeil' and a center of 'center'.

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

 

dunno if it helps, this is the code i use to build a sphere..
https://github.com/s1mpl3x/Buildr/b...e/builder/Buildr_Runnable_Builder_Sphere.java

works fine so far

 

From a quick glance your algorithm seems to be very similar, but you use a costly sqrt function.

DragonSoulSong
Is your sphere supposed to hover in the air? How could under each fire block be a burnable block?

 

I just copied your code into a test project and it seems to work fine. It creates a circle of fire centered at the location specified.

 

Whoa! That's weird...then again, the weirder thing is that I recently rewrote the code because I had this same problem with the old algorithm...but my sphere code was all messed up, so that's why. So I rewrote it from scratch with a correct algorithm this time. Even weirder: I tried replacing the Material.FIRE bit in ignite() with Material.GLASS as a test, and it still placed fire when I re-exported the plugin and reloaded my server...mabey Eclipse is screwing up somehow... Man...if this is an Eclipse issue...I don't know how I'll fix this! I haven't had any problems with other plugins that I'm currently developing...odd...perhaps I could try starting a new project and putting all of the existing code into it, then exporting...I'll try that and let you know how it goes.

EDIT: If you're wondering about what I mean about "the old algorithm", just check out the mainLib.java in the source code for Weapons_of_Legend.

Ok, so I moved all of my code into a new project, re-exported, and reloaded my server and everything works fine now...not sure what that was about. Like I said probably Eclipse being weird. *shrug*

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