public ContrastAdjustmentFilter setBlueExponent(float exponent) {
        this.blueExponent = exponent;
        if (material != null) {
            material.setFloat("blueChannelExponent", blueExponent);
        }
        return this;
    }
Sets the power-law exponent for the blue channel.

@param exponent the desired exponent (default=1 for linear)
@return this filter instance, for chaining
jme3-effects/src/main/java/com/jme3/post/filters/ContrastAdjustmentFilter.java