Finally to add a blurring effect a few pixels behind, change line 5 of main() from this:
vec3 c = sample(0, 0) * dot(n, normalize(lp - sp));[/code:35j7by3f]
to this:
[code:35j7by3f]vec3 c = sample(0, 5) * dot(n, normalize(lp - sp));[/code:35j7by3f]
Come to think it, to make a cel shading like effect, change the same line to something like this:
[code:35j7by3f]vec3 c = normalize(sample(0, 4) * dot(n, normalize(lp - sp)) + sample(0, 5) * dot(n, normalize(lp - sp)));[/code:35j7by3f]