6 ms·
By all accounts, they are working on some sort of device that projects a light field onto the retina. But that is strictly additive. You can't darken anything.
by hemancuso 12y ago
By all accounts, they are working on some sort of device that projects a light field onto the retina. But that is strictly additive. You can't darken anything. This image you see of the elephant in your hand - no way to do that. At best it'd be rather transparent.
Unless there is some aspect of vision that somebody here would like to chime in on [locality on the retinal sensor allowing to perceive darkness by lightening up other areas?], color me deeply skeptical. It seems like "fullscreen" Google Glass, at best.
- mach5 12y agothe article claims they are working on/have an LCD 'masking' layer can black out the area behind the projected light field
- tb100 12y agoYeh, the controllable opacity is really important to the utility of the device IMHO. I've yet to study the linked patent so can't say if that solves it but it's not as simple as just a layer of LCD pixels, as they would not be in focus. It's sort of the same as the light-field generation problem - to generate images at arbitrary depths you need to control both the colour and direction of light rays. To generate sharp occlusions at arbitrary depths using a single 2D "masking" layer will require the layer selectively passing or blocking rays depending on their direction. The patent mentions variable diffraction gratings, which I suspect might be part of the solution to controllable opacity based on ray directions, but I don't know enough about optics really to say for sure.
- tb100 12y agoTo expand upon what the problem is: imagine rays of light reflecting from a point going in all directions (essentially a sphere). A cone of those rays make it into your eye through the pupil. Putting a 2D layer just near to the eye means light from that one point is actually spread across a circle on that 2D layer, with diameter close to the pupil size (getting on for 4mm in indoor lighting). There is therefore significant overlap between the circles from distinct 3D points - so to block out just one of the points you need to selectively block the rays over that entire circle, but only those in the direction of the point we wish to block.
- bri3d 12y agohttps://www.google.com/patents/US20130128230?dq=inassignee:%22Magic+Leap,+Inc.%22&ei=VpdaVI-RMM6oogSW3YKADQ&cl=en https://www.google.com/patents/US20130128230?dq=inassignee:%... This patent describes the "occlusion mask device" which is supposed to do exactly this - darken light coming from certain angles to grant the perception of blackness.
- tb100 12y agoA big unanswered question I have is what the level of transparency is going to be when the display is inactive. For me it needs to be basically 100% to enable an "always worn" piece of hardware. The patents around the lightfield waveguides suggest polarization is used to allow independent optical paths for rays from the real world vs rays coming from the virtual image. Again, I don't know much about optics so wonder if there's an electronic way to have that polarisation turned off for areas without any virtual content, or if there's always going to be a darkening effect on the real world.
- seren 12y agoGiven they have hired creative writers, filmmakers, etc, I don't think they want to create an "always on" device but rather an entertainment device you use at home. See also the article about Brian Cox describing something which sounds similar to a Planetarium like experience on BBC.
- tb100 12y agoMy main point is that making the ideal AR display is hard. To get anywhere close needs controllable opacity and virtual focus planes. From the patents that's definitely the direction Magic Leap are heading in. If such a device exists and is 100% transparent when not in use then there are reasons why you might want to wear it all the time - think notifications like Google Glass but that can be embiggened and responded to on demand in a much larger portion of your field of view. Early hardware is probably not quite going to be there in terms of portability, battery life, fashion, etc. So perhaps it makes sense to focus on in-home use cases first. However in the home-use scenario the value of AR is less clear; an Oculus planetarium may well be better than an AR one in my living room - I don't really want to limit the awesomeness of the size of the universe by the small size of my flat. A lot of cases where AR adds value is in small experiences but deeply context-relevent ones. The consumer value equation for those experiences only really makes sense if the device is always-on. That's the future I think we're heading towards.
- DontBeADick 12y agoThey addressed that in the article that you're commenting on but didn't read.
- hemancuso 12y agoWell that's not fair. The "occlusion mask" is referenced in a patent application, but basically is just a LCD that blocks out light that sits in front of your eye. re: fullscreen google glass, at best.
- ctdonath 12y agoWell, that's exactly the point: an anti-display which lets through what parts of reality the system wants you to see, and blocks light from what it wants you to not see - so another display can render something to fill in the blocked-out areas. Rather than the "ghosting" of putting an elephant over your hand, with the light of both being added, the LCD acts as a dynamic precision cutout shutter, blocking the light from where the elephant would be and letting another display fill in _all_ the light you'd expect from that visual addition.