kilian@poplar.cray.com (Alan Kilian) (05/29/91)
> From: galt@dsd.es.com (Greg Alt - Perp) > Also, are there any reasons why I would want to pay $400+ > to get a Private Eye when I can get a sony watchman for only $100? If you want to put the watchman about 8cm from your face and the watchman is about 5cm wide by 5cm tall then you can get about a 60 degrees viewing angle. The optics would be simple. Just a simple lens with an 6cm focal length. you can experiment with the lens to eye distance to get comfortable. The lens to watchman distance is 6cm the same as the focal length. I think that you want two watchmen also. One for each eye even if they are not doing stereoscopic images. Each display can receive the same video input. > I only want sit-down VR. I am perfectly happy > with being restricted to my chair, with only head rotations (and not > position) being used. This makes things much simpler. > Could it be done with a bunch of > mercury switches? (but then, there is the problem of Y axis rotation). > Maybe Y axis rotation could be obtained by rotating the chair? > Is Z axis rotation (tilting your head sideways) really that important? > If you use only rotation, you could possibly use the 4 analog inputs > available on the game port. > Also, what sort of resolution would be necessary? The range is is about > 120 degrees for X rotation, 170 for Y, and 90 for Z. I would think > 5 degress would be sufficient (which means you would only need 5 bits of > info per axis). Does anyone know how many bits you can get from a > game port? > Greg First I like to use "pitch" for looking up or down, "yaw" for looking left or right and "roll" for rotating your head about the normal vector from your nose clockwise or counterclockwise (Tipping your head) So if you only want to do pitch and yaw it's pretty easy. Put a variable resistor from a game paddle on your chair to get the yaw angle. and make a game paddle with a pendulum hanging from it and use gravity to get the pitch angle. Like this: ||||||||||||| +-------------+ | | | o o |== <-- The variable resistor | > |====+ <-- shaft of variable resistor Your head ---> | O |== | (Nothing personal) | | | <-- shaft of pendulum +-----+ +-----+ | Your "pencil" neck --> | | O <-- weight You could use super glue to attach the variable resistor to your head. It would be a good idea to shave a patch of hair to get good skin contact. Make sure not to cover up an ear or you won't get good stereo hearing. Then run the wires from your chair and head to two game ports on your machine and from then on it's just "A simple matter of programming" Good luck and have fun, -Alan Kilian -Alan Kilian kilian@cray.com 612.683.5499 Cray Research, Inc. | If god had meant us to use the metric system 655 F Lone Oak Drive | he would have given us ten finger and ten Eagan MN, 55121 | toes. The author of _Lighter Elements_