The core of interaction design is the see-think-do loop that describes the outputs, human cognition, and inputs of an interactive system. A film or TV show spends time showing inputs without describing some output, only when these users are in the background and unrelated to the plot. But there are a few examples of outputs with no apparent inputs. These are hard to evaluate in a standard way because it’s such a giant piece of the puzzle. Is it a brain input? Is the technology agentive? Is it some hidden input like Myo‘s muscle sensing? Not knowing the input, a regular review is kind of pointless. All I can do is list its effects and perhaps evaluate the outputs in terms of the apparent goals. Ghost in the Shell has several of these types of inputless systems. Today’s is Kusanagi’s heat vision.

Early in the film, Kusanagi sits atop a skyscraper, jacked in, wearing dark goggles, and eavesdropping on a conversation taking place in a building far below. As she looks down, she sees through the walls of the building in a scanline screen-green view that shows the people as bright green and furniture as a dim green, with everything else being black.

She adjusts the view by steps to zoom closer and closer until her field of vision is filled with the two men conversing in her earpiece. When she hears mention of Project 2501 she thinks the message, “Major, Section 6 is ready to move in.” She reaches up to her right temple and clicks a button, to turn the goggles off before removing them.

That’s nifty. But how did she set the depth of field and the extents (the frustum) of the display so that she only sees these people, and not everyone in the building below this? How does she tell the algorithm that she wants to see furniture and not floor? (Is it thermography? Is the furniture all slightly warm?) What is she doing to increase the zoom? If it’s jacked into her head, why must she activate it several times rather than just focusing on the object with her eyes, or specifying “that person there?” How did she set the audio? Why does the audio not change with each successive zoom? If they’re from separate systems, how did she combine them?

Squint gestures

If I had to speculate what the mechanism should be, I would try to use the natural mechanisms of the eye itself. Let Kusanagi use a slight squint gesture to zoom in, and a slight widening of the eyelids to zoom out. This would let her maintain her gaze, maintain her silence, keep her body still, and keep her hands free.

The scene implies that her tools provide a set amount of zoom for each activation, but for very long distances that seems like it would be a pain. I would have the zoom automatically set itself to make the object on which she is focusing fill her field of vision less some border, and then use squint-gestures to change the zoom to the next logical thing. For instance, if she focused on a person, that person would fill her field of vision. A single widening might zoom out to show the couch on which they are sitting. Another the room. This algorithm wouldn’t be perfect, so you’d need some mechanism for arbitrary zoom. I’d say a squint or wide-eyed gesture held for a third of a second or so would trigger arbitrary zoom for as long as the gesture was maintained, with the zoom increasing logarithmically.

As for the frustum, use the same smart algorithm to watch her gaze, and set the extents to include the whole of the subject and the context in which it sits.