void createContours() {
		colorFractionBase = defaultColorFractionBase;
		colorFractionRange = defaultColorFractionRange;
		setMapRanges();
		float min = valueMappedToRed;
		float max = valueMappedToBlue;
		float diff = max - min;
		Logger.info("generateContourData min=" + min + " max=" + max + " nContours=" + nContours);
		for (int i = 0; i < nContours; i++) {
			contourIndex = i;
			float cutoff = min + (i * 1f / nContours) * diff;
			/*
			 * cutoffs right near zero cause problems, so we adjust just a tad
			 * 
			 */
			generateContourData(cutoff);
		}
	}