Volumetric Displays: Passive Optical Scatterers

Рет қаралды 26,470

8 жыл бұрын

Project Page: www.cs.columbia.edu/CAVE/proje...
The goal of this project is to develop a very inexpensive class of volumetric displays that can present certain types of 3D content in a compelling way. The types of content we wish to display are simple 3D objects, extruded objects and 3D surfaces that appear dynamic when projected with time-varying images. Our displays use a simple light engine and a dense cloud of passive optical scatterers. The basic idea is to trade-off the (2D) spatial resolution of the light engine to gain resolution in the third dimension. The simplest way to achieve such a trade-off is to use a stack of planar grids of scatterers where no two stacks overlap each other with respect to the projection rays of the light engine. However, such a semi-regular 3D grid suffers from poor visibility; as the viewer moves around the point cloud the fraction of points visible to the viewer varies dramatically and is very small for some of the viewing directions. Our key insight is to randomize the point cloud in a manner that is consistent with the projection geometry. We have verified that when a point cloud is randomized in a specific manner it produces a remarkably stable visibility function.
We have explored several ways of creating dense clouds of passive scatterers. We have chosen to use Laser Induced Damage (LID) technology which can very efficiently, precisely, and at a very low cost embed the desired point clouds in a solid block of glass. Each scatterer is a physical crack in the glass that is created by focusing a laser beam at the point. When a point in the cloud is lit by ambient light it is barely visible, but when it is lit by a focused source it glows brightly. We have studied the radiometric and spectral characteristics of LID scatterers and found that they have the properties needed to display objects in color and with sufficient brightness to be viewed within a 120 degree cone that is aligned with the projection direction. For illuminating the scatterers, we have developed an orthographic light engine that uses an off-the-shelf projector and inexpensive optics to create parallel rays with a large footprint. Orthographic projection enables us to use point clouds without resolution biases and makes the calibration of the display relatively straightforward.
We have developed several versions of our volumetric display, each one designed to meet the needs of a specific class of objects or a specific application. We have implemented point clouds with 10,000 points for the display of true 3D objects, 190,500 points for the display of extruded objects with arbitrarily textured top surfaces, 180,500 points for the display of purely extruded objects, 83,866 points for the extension of the game Pac-Man to 3D, and 127,223 points for the face model used to create a 3D avatar.
This video describes the working principle of our volumetric displays as well as several examples of objects shown using the displays. Examples of true 3D objects and extruded objects are shown. In addition, the 3D Pac-man and 3D Avatar are shown. (with narration).

Пікірлер: 22

@robb233 7 жыл бұрын

Love this work, but I find best way to convey depth in video format, is not to show 4 views simultaneously, but one view of a non-animated object, while the camera pans around it sufficiently.

@skyr8449 6 жыл бұрын

idk, I think this way is better.

@svperuzer 3 жыл бұрын

Well, you can just pan around an animated object as well, and I think, should be the most compelling

@robb233 3 жыл бұрын

@@svperuzer Panning around an animated object would look interesting but I've seen other demos where the presenter uses the animation to hide the fact it's a 2d display unfortunately.

@svperuzer 3 жыл бұрын

@@robb233 yeah I considered that after posting the comment

@SeanHodgins 2 жыл бұрын

It makes sense why this showed up in my feed...

@PeterChamor4 2 ай бұрын

It makes sense why there was corn in my toilet this morning

@mikelastname9444 6 жыл бұрын

I wonder if the light scattering points could be constructed in a way which would refract light in predictable directions, so that depending on the direction of the light entering the point, you would get different visual outputs. Instead of projecting light onto the scatterers with a single projector, you could use multiple projectors at different angles. This way, the light which is outputted from each scatter point would only project to those directions which would be naturally visible in the real world object. The effect this would have is that the displays wouldn't be 'transparent;' They would look like solid objects, with different properties depending on where you viewed them from. This might even be possible with a single projector. Imagine that each scatter point is shaped like an inverted 'teardrop,' with the point facing down. Depending on where the beam of light hit the scatter point, it could be configured to reflect to pretty much any direction. If it were possible to precisely control the beam, a single beam could be scattered in a very precise pattern of directions. It might be necessary to use a laser array to get that level of precision.

@JustIn-sr1xe 2 жыл бұрын

So, we're making the floating face dude from power rangers now?

@tnaplastic2182 4 жыл бұрын

The rolling Sphere looks like a Pokeball!

@fredtretout 6 жыл бұрын

i really curious about how you create the block of glass with laser induced damage. What is the hardware and if there is some limitation of size?

@BrainSlugs83 6 жыл бұрын

I think it's like what they have in the kiosks at the mall -- where they put your face in a piece of glass or something. -- I don't know what it's called, but they have the machine there where they make it. -- Seems like a great idea.

2 жыл бұрын

@@BrainSlugs83 i also think that exactly this is the technology the use here for the solid. as fare as i know the limits here are lens focus ranges. so more a *do i have the correct optics* question.. (the laser beam must be focused in the glass - so it has to enter the glass with a wide diameter..) down the rabbit hole: - the German Wikipedia article has some more information: de.wikipedia.org/wiki/Glasinnengravur - and on of the manufactures also: www.vitro.de/neu_/industrial/standard-systems/industrielle-standard-systeme.html - in there datasheets the z-height is all mentioned with 95mm. - and i found a resolution of ` > 250 dpi marking possible in sub-mm-area` that would convert to 0,1016 mm -- that calls for a very high resolution projector and a very accurate alignment ;-)

@MrFrost-xh6rf 7 ай бұрын

this was in 2006!?!?

@MikaelMurstam 6 жыл бұрын

Voxiebox blows this out of the water though =)

@lost4468yt 5 жыл бұрын

This was from 2006.

@robb233 3 жыл бұрын

Voxiebox is great. But it's an actively driven high speed mechanical display. This one is interesting to think about because it's passive with no high speed timing requirements. Different approach.

@mrkiky 6 ай бұрын

@@robb233 yep, the voxiebox approach (also voxon which seem to have made more recent and bigger versions of the same thing) probably makes a ton of noise (never seen it on video without music over it). I like this approach more and if it could be perfected to higher resolutions, could be quite cool and usable. The block of acrylic just needs a denser cloud of smaller laser etched points, the projector needs to be higher res and higher refresh rate, and you'll have something good looking.