Overview
Make distant things small, close things large. Sprite scaling created convincing 3D without true 3D hardware. Racing games showed cars growing as they approached. Shooters had enemies rushing toward the player. The technique powered the “Super Scaler” arcade era and brought pseudo-3D to home systems.
Fast facts
- Purpose: Simulate 3D depth.
- Method: Size sprites by distance.
- Peak: Mid-1980s to early 1990s.
- Hardware: Often required custom chips.
How it works
| Step | Process |
|---|
| 1 | Calculate object distance |
| 2 | Determine scale factor |
| 3 | Draw sprite at scaled size |
| 4 | Position based on perspective |
Sega Super Scaler
| Game | Year | Innovation |
|---|
| Hang-On | 1985 | Motorcycle racing |
| Space Harrier | 1985 | Into-screen shooter |
| Out Run | 1986 | Driving with scenery |
| After Burner | 1987 | Air combat |
| Galaxy Force | 1988 | Space combat |
Implementation approaches
| Method | Requirement |
|---|
| Hardware scaling | Custom arcade chips |
| Pre-scaled sprites | Multiple sprite versions |
| Real-time software | CPU intensive |
| Mode 7 (SNES) | Hardware rotation/scaling |
Pre-scaled sprites
| Distance | Sprite version |
|---|
| Far | 8×8 pixels |
| Medium | 16×16 pixels |
| Close | 32×32 pixels |
| Very close | 64×64 pixels |
Requires multiple versions of each sprite in ROM.
Mode 7 (SNES)
| Feature | Capability |
|---|
| Background scaling | Real-time |
| Rotation | Any angle |
| Sprites | Not scaled by Mode 7 |
| Games | F-Zero, Mario Kart |
Software scaling
| Platform | Performance |
|---|
| Amiga | Blitter-assisted |
| Mega Drive | CPU scaling routines |
| PC | Later VGA games |
Limitations
| Constraint | Effect |
|---|
| Memory | Multiple sprite copies |
| CPU | Real-time calculation |
| Quality | Pixelation at large sizes |
| Animation | Each frame needs all scales |
See also