Ant Attack

Ant Attack was published by Quicksilva in late 1983 for the 48K ZX Spectrum at £6.95, written by Sandy White with Angela Sutherland.

You are in Antescher, a walled city rendered in what the packaging called Soft Solid 3D, and its only other inhabitants are enormous ants that eat people. Someone is trapped in there. You go in with a supply of grenades and bring them out.

It is the first isometric game on the Spectrum, a year before Knight Lore, and it is one of the few games of the period whose design decisions still read as deliberate rather than as constraints.

Fast facts

• Publisher: Quicksilva · Author: Sandy White, with Angela Sutherland
• Released: 1983 · Price: £6.95 · 48K, machine code
• CRASH: 85%, issue 1, page 18 — the magazine’s index files it under the engine name, “Soft Solid 3D Ant Attack”
• Sales: 50,000 by December 1984 — marked with a “gold cassette”, only the second ever awarded, presented by Radio 1 disc jockey Annie Nightingale
• Later: re-released on the Spectrum through Creative Sparks, and converted to the Commodore 64

How the 3D works, and why it could work at all

CRASH ran a feature on Spectrum 3D techniques in July 1984 and used Ant Attack as its worked example of isometric perspective. Its explanation is the clearest period statement of why the technique suited an 8-bit machine:

With Isometric Perspective the programmer’s life is much easier because the scenery only has to be defined once as it doesn’t change shape physically during the game. Look at Ant Attack (Quicksilva) and you’ll see this exactly. The city is a large graphic over which the screen scrolls, so the only problem is the scrolling, the blocks of the city don’t have to be redefined with every movement.

That is the whole trick. In a perspective projection, every object changes shape as you approach it, so each one needs to be redrawn at many sizes — which is memory the Spectrum did not have. In an isometric projection a cube is the same cube wherever it is on screen, so a city is a tiling problem and a scrolling problem, not a rendering one.

CRASH also names the cost, and it is a real one: “the game can only be played from one height as it is only from a strictly fixed vantage point that the isometric perspective will work.”

White’s answer to the other isometric problem — that things hide behind other things — was to let the player move the camera. There are four viewing angles, switchable, so you can look round a wall from a different corner. The playing area is much larger than the screen and scrolls in both axes under the cursor keys.

See isometric projection for the geometry.

A sculptor’s game

CRASH’s first issue, reviewing it in February 1984, put its finger on where the game came from in one sentence: “Sandy White is a quiet Scot and a sculptor by trade. His understanding of three dimensional construction is evident in his game, Ant Attack.”

That is not a reviewer reaching. White had an art-college degree and had shown sculpture in Aberdeen before he wrote a game, and he had come to computers by building one — a Sinclair MK14 — to drive a working sculpture. See Sandy White.

The choice at the start

Before the game begins, you choose whether to play as a man rescuing a woman or as a woman rescuing a man. In 1983.

ACE, putting the game into its Hall of Fame in 1990, thought this was the thing about Ant Attack that nobody mentioned and should: “there’s one aspect of Ant Attack not yet mentioned that really does make it almost unique. It comes right at the start where you choose to be a man rescuing a woman or vice versa. No stereotyping in Antescher. But then again, in those innocent days, program authors actually paused to consider…”

It costs the game nothing — two sprite sets — and no other Spectrum game of the period bothered.

Why it matters here

Ant Attack is the cleanest example in the Spectrum catalogue of a technical constraint producing a technique rather than a compromise. The machine could not do perspective, so White used a projection where perspective is not needed, and the result does not look like a machine getting away with something. It looks like a decision.

That the person who made it thought in three dimensions for a living, and had built his own computer to move a sculpture, is the part worth remembering when the history gets told as a story about programmers.

See also

• Sandy White — the author.
• Quicksilva — the publisher.
• Isometric projection
• Knight Lore — a year later, and usually credited first.
• Sinclair ZX Spectrum