Pixie supports true area light sources. That means, the area light source shader will be executed on the surface of the area light source and thus can use any geometry variable related to the attached surface. "numarealightsamples" attribute control the number of points for each individual primitive that Pixie will sample on the light and execute the light shader. Each of these sampling points are treated as individual light sources in the diffuse, specular calls and inside the illumination statement. Note that each primitive will be sampled separately. So if there are 10 primitives inside a light source and the number of area light samples is 5, 50 samples will be collected/shaded. I know this sucks. The theoretically correct way of operation is to sample a fixed number directions uniformly sampled toward the light source from the point being shaded. However, this sampling is quite difficult. I have some ideas about this though, stay tuned. Area light source tip: avoid using complicated area light sources :).