gummy texture
*raise eyebrow*
I'll admit the idea for the texture strip is a little out there. I have no intuitive idea whether, when you put them in little squares, a blind person could recognize just a few textures or thousands. I'm thinking of it mostly as a way to try to increase the resolution without actually increasing the resolution. I mean, in theory you could have one pin per pixel on the video monitor, and the reader could feel letters directly by whether pins are in one of two positions, but that's a lot of pins. Or you could have an array of large squares covered by textures (even a flat array with no actuators except to pull strips over individual squares) and the person might be able to feel this texture is an A, that one a Z. But I don't really believe either of these is very feasible (one because of the fabrication involved, one by what people can feel), so I'm hoping you can strike an average, then lump in more features combinatorially until you get something useful.
The other question is how far the pins should be able to go up and down. In theory, just two positions a millimeter apart should be enough to feel a black-and-white pattern... I think? On the other hand that cute MIT prototype makes me think you could program the entire
landscape so a blind person could feel how the DF world is in 3D.
For a true 3D DF display for the blind: Though what to do about the hidden layers is an issue... I'm picturing, what if the pins could feel when you drag them in one of four cardinal directions? Then, say, you could define pushing a pin "downward" (i.e. down arrow on a video screen, rather than pushing it down into the device) to mean that you want to look at the 3D layer just under the layer that pin is at. So all the pins on the device withdraw to one level less than the pin you pushed was at, and reset their textures and any braille patterns they might or might not have the resolution to offer to correspond to the 2D map at that Z-level only. But the ones lower than that remain 3D. Push a pin "up" on the screen, and the cut is moved up one Z-level, so any pins that correspond to positions that go up higher than that move up. If you are pushing toward a mountainside, it should be possible to let your fingers ride up with the pins, sliding along from one to the next, until the effect of pushing the first pin down is undone.
Whatever kind of display, it should be possible for it to interpret single clicks and double clicks by tapping on the pins at a given spot., in addition to the effect of a gentle pressure as I described last post.
Anyway, getting back to the texture strip: this is limited in that the textures have to be really durable, even though the strip would bend nearly 90 degrees at each side of the tip, and be pulled around the tip with every single change of display. That's a lot of wear and tear so they really
really gotta be made out of good durable stuff. That's another reason why you might not be able to have many textures. I suppose that if you just have two or four textures or so you could arrange it with some sort of simple swivel mechanism behind the head that wouldn't require any flexing. When feasible the existing textures should be different colors so a sighted person can conveniently troubleshoot, or if he starts to envy those 3D scenes, play with them himself.