The only other hint we received about the technical prowess of the Wii U came from the Japanese garden demo, which shows a bird taking flight, landing on a tree branch which blossoms into flower, before returning to the skies again, soaring over water, where the scenes shifts to a fish leaping out towards the camera.
The water effect is one of the most impressive elements of the demo. The surface looks similar to the tessellated fluid surfaces added to Unreal Engine 3 during the Gears of War 2 development work, with a pleasing 3D volume to the effect that's most especially noticeable when the fish is just above or below the water line.
There is actually a whole lot more to the Japanese garden demo than what was shown in the media briefing. Different weather effects kick in - for example, rain begins to descend, interacting very nicely with the surface of the water, with a huge amount of tiny splashes impacting on the "skin" of the fluid.
Other sections of the demo unseen in the media briefing were also witnessed: for example, a close-up of the bird on a snowy ledge, with the snow itself deforming beneath it - a really nice effect, but not particularly taxing from a technical perspective (readers may recall something similar in Dead or Alive on the Xbox).
In addition to this, there's a night-time flying section where bad weather kicks in, with a lot of fast-moving rain particles. At this point, the frame-rate really tanks. Curiously, the performance is fine in the snow scene that you might assume is using similar tech, so quite why the frame-rate drops as much as it does at this point is unclear. Another additional section shows the whole scene bathed in an intense orange bloom effect, without any tone-mapping. Artistically it seems to fit the scene well enough but the lighting definitely isn't using high dynamic range rendering.
Overall frame-rate in the elements of the demo seen in the conference is solid at 30 frames per second (again confirmed by looking at an off-air TV recording), but in the latter, unbroadcast sections we do see a lot of variance in performance. The fact that the player can adjust the camera view also adds to the fluctuating frame-rate.
It's a shame that the demo hasn't been seen in its entirety, and not even a decent HD video of the section shown in the media briefing has been released by Nintendo. While the demo is impressive, with some wonderfully realistic animation on the bird itself, many of its shortcomings have been hidden by the low quality video streams we've had to look over.
Texture shimmering is a significant problem in certain sections of this demo. Early in the sequence, before the scene where the bird lands and the cherry blossom... blossoms, there's a lot of shimmering in the foliage, which looks to be an alpha-testing issue. We see a similar artifact later on in the demo too, on the ground and on a passing tree just before arriving at the pond.
Quite why this is happening is unclear. Maybe the coders implemented negative LOD, using far higher texture detail than would comfortably fit into the available resolution. Maybe it's just poor texture filtering - which we really wouldn't expect from a modern graphics core, but could be an option. We're not entirely clear on resolution and anti-aliasing here, but it's definitely not a 1080p demo, so our best guess is that like the Zelda HD experience, it's also running at 720p.