By Graham K. Rogers

When features of the iPhone and iOS 8 release were being demonstrated at Apple's 2014 World Wide Developers Conference in San Francisco in June this year, Epic Games were able to show the lifelike effects they had been able to produce with the new graphics engine - Metal - with a well-applauded rendition of a house and garden. But it was not just any house or garden.

The improvements to iOS made it possible to make minor, but very realistic changes to visual displays. Particularly interesting were the realistic leaves that fell from a tree, water movement when the user touched the screen, and the motion of fish in a pond. This was not a totally new idea as one of the early apps I downloaded (and still use) was Koi Pond: a fairly lifelike display of fish that would interact with user input.

The free Epic Games app, Epic Zen Garden has just been updated. Part of the description in the iTunes Store reads, "3,500 butterflies equal roughly 4,000 draw calls, with falling petals at 5,000 particles (not draw calls). . . ."

When started, the display in the app moves around like a movie, but when the user taps the screen, it pans and zooms out. Three small circles indicate where a user might tap the screen. In that initial state, the fish can be seen swimming and tiny birds fly in and out of the patio area.

Homing in on the bare tree, touching the branches creates an instant blossoming, but with the slight breeze, the petals begin to fall one by one, showing the power of the graphics. A circle to the top right allows all the leaves to be removed and the user can start again. A triangle top left, zooms back to the larger view.

Another small circle zooms out so we can view the house perched on a floating rock, which reminded me of some scenes in James Cameron's, Avatar. Homing in on the pond, the fish will be attracted to movement of water when the user taps the screen; and past the pond it is possible to draw patterns in the sand of the Japanese garden. In one corner of the sand garden is a pool. Touching the bamboo water pipe tips more water into a basin and the area is filled with butterflies.

While this is essentially a rather sophisticated demo app, the sheer beauty of what a user can do with the Metal engine makes this rather interesting in terms of entertainment. Like Koi Pond, it could easily allow a user to while away hours in a day just relaxing.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs. He is now continuing that in the Bangkok Post supplement, Life.