public double getXOffset() {
        return this.xOffset;
    }

    /**
     * Returns the y-offset for the 3D effect.
     *
     * @return The 3D effect.
     */
    public double getYOffset() {
        return this.yOffset;
    }

    /**
     * Sets the x-offset and sends a {@link RendererChangeEvent} to all 
     * registered listeners.
     * 
     * @param xOffset  the x-offset.
     */
    public void setXOffset(double xOffset) {
        this.xOffset = xOffset;
        fireChangeEvent();
    }

    /**
     * Sets the y-offset and sends a {@link RendererChangeEvent} to all 
     * registered listeners.
     * 
     * @param yOffset  the y-offset.
     */
    public void setYOffset(double yOffset) {
        this.yOffset = yOffset;
        fireChangeEvent();
    }

    /**
     * Returns the paint used to highlight the left and bottom wall in the plot
     * background.
     *
     * @return The paint.
     */
    public Paint getWallPaint() {
        return this.wallPaint;