Create a drop shadow

shadow.lua

local function shadow( width, height, size )
	local g = display.newGroup()
	g.x, g.y = display.contentCenterX, display.contentCenterY
	
	display.newRect( g, 0, 0, width+size, height+size ).fill = {1,1,1,0}
	display.newRect( g, 0, 0, width, height ).fill = {0,0,0}
	
	local c = display.capture( g )
	g = display.remove( g )
	
	c.fill.effect = "filter.blurGaussian"
	c.fill.effect.horizontal.blurSize = size
	c.fill.effect.horizontal.sigma = size
	c.fill.effect.vertical.blurSize = size
	c.fill.effect.vertical.sigma = size
	
	c.alpha = .3
	
	return c
end