public ContrastAdjustmentFilter setRedScale(float factor) {
        this.redScale = factor;
        if (material != null) {
            material.setFloat("redChannelScale", redScale);
        }
        return this;
    }
Sets the output scale factor for the red 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