Smoothing simplex noise

Newbie & Debugging Questions
#1

So I plugged in some code and made a color coded simplex noise generator as the first step towards generating terrain. I have these values:

Reds are higher values while yellows are lower values. As you can see, the values are kind of choppy and I want to smooth out these values.

Any ideas?

CopyableCougar4

#2

Lower the frequency (divide the input values by a larger number)

#3

Is this a good approach? I take the average of the four surrounding points and “soften” the inputted value by a given factor. Here is my “softening” method called [icode]normalize()[/icode].

private double normalize(double value, int x, int y) {
		double leftRightAvg = (heightMap[x - 1][y] + heightMap[x + 1][y]) / 2;
		double bottomTopAvg = (heightMap[x][y - 1] + heightMap[x][y - 1]) / 2;
		double avg = (leftRightAvg + bottomTopAvg) / 2;
		double delta = value - avg;
		delta *= NORMALIZER;
		return avg + delta;
	}
	
	private double NORMALIZER = 0.85;

Is this a good idea? Any other ways to smooth out the values?

CopyableCougar4

#4

Do what HeroesGraveDev says. If you smooth those speckles, your terrain won’t look very interesting.

#5

This is my current code:

private double dampen(double value) {
		return value * DAMPENING + OFFSET;
	}
	
	private double normalize(double value, int x, int y) {
		double leftRightAvg = (heightMap[x - 1][y] + heightMap[x + 1][y]) / 2;
		double bottomTopAvg = (heightMap[x][y - 1] + heightMap[x][y - 1]) / 2;
		double avg = (leftRightAvg + bottomTopAvg) / 2;
		double delta = value - avg;
		delta *= NORMALIZER;
		return avg + delta;
	}
	
	private double NORMALIZER = 0.75, DAMPENING = 0.55, OFFSET = 0.15;
	
	public void generate() {
		SimplexNoiseGenerator.genGrad(new FastRand(seed));
		for (int pointer1 = 0; pointer1 < heightMap.length; pointer1++) {
			for (int pointer2 = 0; pointer2 < heightMap[0].length; pointer2++) {
				heightMap[pointer1][pointer2] = dampen(SimplexNoiseGenerator.noise(pointer1, pointer2));
			}
		}
		for (int pointer1 = 1; pointer1 < heightMap.length - 1; pointer1++) {
			for (int pointer2 = 1; pointer2 < heightMap[0].length - 1; pointer2++) {
				heightMap[pointer1][pointer2] = normalize(heightMap[pointer1][pointer2], pointer1, pointer2);
			}
		}
	}

I guess I invisioned (because this is my first dive into simplex noise) that there would be smooth drops around a few peaks. Where should I search for achieving something like this?

CopyableCougar4

#6

try

SimplexNoiseGenerator.noise(pointer1*0.001f, pointer2*0.001f)

if noise() takes float arguments.

#7

Thanks, but it takes doubles.

[icode] public static double noise(double xin, double yin)[/icode]

CopyableCougar4

#8

thats same good :slight_smile:

SimplexNoiseGenerator.noise(pointer1*0.001, pointer2*0.001)

should get you forward.