Diegetic UI vs Skeuomorphism
ダイエジェティックUI / スキューモーフィズム
Both sit in UI Expression, so the question is not what they belong to but how they behave. One is technique and the other style. They are reached for with different intent, which is the fastest way to tell them apart.
Diegetic UI
A name for the corner of game interface design where an element belongs both to the fiction and to the three dimensional world. A 2009 master's thesis at Chalmers University of Technology, written with EA DICE, mapped game UI on those two axes and reserved the word for that corner. Health glowing on the hero's own suit is the type case.
Skeuomorphism
Borrows cues from real materials and tools to make unknown interactions understandable. It names the principle, so Aqua and Brushed Metal are what the principle looked like when one company shipped it.
| Diegetic UI | Skeuomorphism | |
|---|---|---|
| Era | 2009– | 2000s–2010s |
| Family | UI Expression | UI Expression |
| Kind | Technique | Style |
| Cues | Health or ammunition shown on the protagonist's own equipment instead of in a corner of the screen / A map the character holds up and reads while still walking, rather than a paused overlay / Panels of information projected into the air that tilt with the camera because they occupy the space / Directions given by the color of a signpost standing in the world itself | Leather, metal, paper / Dimensional shadows / Real-world metaphors / Fine textures |
| Best used for | Moving health and ammunition out of the corners of a first person game and into the world itself · Placing information in VR or in a vehicle as an object in space rather than a layer stuck to the view | Explaining new interactions through familiar tools · Crafted, tactile experiences |
| Type | Treat every character as printed or projected onto something in the world, so it skews with the camera. Some angles will be unreadable, so carry the same meaning in shape and color too. | A humanist face suited to the purpose |
| Composition | Leave the four corners of the screen empty. Distribute information across the body, the held device, and the environment, and keep those roles fixed. | Adopt the structure of the real tool |
| Material | Use only materials the fiction can account for, such as a lit tube or a projected plane. The style collapses when the material stops being explainable, so settle the world first. | Precision texture only where it serves function |
| Caution | Building an object into the world and then printing controller button names on it mixes fiction with rules, and that is exactly where the thesis's own focus group reported the illusion breaking. | Ornament must not bury the interaction. Expect generations who don't share the metaphor. |