public ContrastAdjustmentFilter setGreenScale(float factor) {
        this.greenScale = factor;
        if (material != null) {
            material.setFloat("greenChannelScale", greenScale);
        }
        return this;
    }
Sets the output scale factor for the green channel.

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