cybereality wrote:Sounds good, geekmaster. I always thought that fresnels would work well.
I am surprised at how well it worked with these newer cheap fine-pitched fresnel lenses. By stacking them, I am taking advantage of the extreme off-center distortion from the edges of these 6-inch diamemeter lenses. Due to my stacking arrangement it does not stretch vertically near the edges as much as horizontally, but still it looks amazing, and the correction you used in your "rift-adjusted" video actually shows doorways as rectangular in these lens stacks. There is more chromatic abberation near the edges (mostly blue), but that could be adjusted in software. Even when I rotate my eyes in their sockets (painfully) to their extreme positions, all I can see is video (even where my nose should be), giving me a
"supernatural" FoV.
For low-power devices (no GPU) I plan to use a software displacement map to do the geometric and chromatic correction, like this:
I used displacement mapping like this for animated "magnifying glass" effects back in the early 90's, when 360x480 256-color VGA (Michael Abrash's "Mode X") and 386 CPUs were state-of-the-art. It should work well on low-power devices to correct for lens distortion.
BTW, the fresnel lenses that came with the cardboard "HMD" in the "Virtual Reality Creations" book were much coarser pitch than these dollar store fresnel lenses, and consequently did not work as well. Here is that book:
http://books.google.com/books/about/Vir ... AIAQAAMAAJ
And these are listed at Amazon as "new", so may even come with the fresnel googles:
http://www.amazon.com/gp/offer-listing/ ... dition=new
I have been into 3D for about 55 years now. It was always a big thing in my family. I have my grandmother's stereopticon viewer and a large collection of 3D cards for it:
I was thinking about trying to stick my Nexus 7 into my stereopticon in place of a 3D card. A classic steampunk HMD, for sure...