In a recent interview you have revealed Oblivion's engine is capable of sophisticated lighting across surfaces (normal mapping and parallax mapping, for instance). How would you characterise your experience with parallax mapping and its junction and texture warping problems?

We avoid texture warping on high-end cards by doing the eye vector calculation per-pixel instead of per-vertex. Some amount of texture warping is inherent to the system no matter what card you’re using, but overall we find it to be virtually a non-issue in game unless you’ve got the camera mashed up against the textures. The artists quickly learned the limits of range in the displacement for what looks good and what looks bad. T-junctions are a problem for just about any lighting calculation, so these are mostly avoided in the art creation stage by being smart about how we construct objects.​