The Lighting effect allows the developer to specify lighting sources with coordinates of where the light is coming from. Unfortunately, the coordinates are not adjusted for the coordinate transform of a node and are actually relative to its bounding box, which makes positioning the lights properly for an arbitrary node very tricky.

This bug also manifests readily when we render on a retina display where all nodes are rendered with an implicit 2x scale.

Two test programs are attached. The "Scaled" version should look like a double-sized version of the regular test case, but the light is displaced in the scaled version.