IMM 3D Vision Fall 2009

Stereo Scopic 3D in Maya

3dvisionclub — Fri, 18 Dec 2009 20:06:29 +0000

Here are some definitions to help you understand the basic principals behind 3D illusions

Stereo-Opsis: The ability to see depth. By using both eyes, whenever some one looks at an object they are seeing the same image through both sources that are slightly shifted. An average adult has a distance of 6.5 cm between their eyes.

To simulate 3D on a 2 dimensional plane, a computer screen or television, you must show two sets of images, one set per each eye.

There are couple of ways of accomplishing this. Shutter Glasses, Ana-glyph, Polarization.

Shutter Glasses: A set of glasses that will block the vision of the right eye, when showing a image for the left eye, and turn off the left eye when showing the image for the right eye.
To do this you need a pair of expensive glasses, a 120HZ monitor or television that will allow for double the frame rate, as is shows twice the amount of frames. You also need a connection that will synchronize the shuttering of the glasses with the content being displayed.
At the current time (December 2009), the most popular Shutter Glasses are available through Nvidia called 3D vision

http://www.nvidia.com/object/3D_Vision_Overview.html

In order to get them going you also need to install additional drivers for the video card. The great thing about them is that there is plenty of Media for them, many best sellers available for a PC platform will be playable in 3D content. Making this a very desirable product for any hardcore gamers who are willing to pay an average of $300 dollars for the glasses, $200 for the video card and $300 for a 22inch 120Hz lcd monitor.
Many lcd tvs are 120Hz and have a DVI connection, the very same one used to connect computer monitors.

Polarization: Polarization is mostly used in 3D theaters. The left eye will have horizontal lines running through it and the right eye will have vertical lines running through it. Also the content is no longer one image, there are two projects running from different angles one with horizontal and the other vertical lines running through it.
The advantage is that glasses are inexpensive to make, and can be easily washed an reused at the theaters. This for most part can not be used in a home environment, as not that many people have two projects at home.
The disadvantage of this technology is that if the viewer rotates their head, the vertical and horizontal lines will no longer match up with the vertical and horizontal lines on the screen and the illusion of 3D will be lost.
To correct this, instead of using horizontal and vertical lines, many theaters use spherical lines that turn clock wise and counter clock wise to seperate the two images.

Ana glyph: Uses a pair of color glasses, red for the left eye, and green and blue for the right eye. By coloring the glasses by different color you are limiting the color range of what each eye can see. The left eye can only see red colors, and the right eye can only see green and blue colors.

The advantages are the Ana glyph glasses are very inexpensive, however the color changes they make are too severe and will not go main stream. In order for them to work properly the content must not use very saturated colors that are either very red, or very green and blue. Natural earth tones will look great.

For this I’ve used a Maya 3D scene of a building that I have been working on and created a stereo-scopic camera. What it does, it creates three cameras, one for the left eye, one for the right eye, and the center camera that overlays them both. Both the left and right cameras are simulating two eyes, they are slightly separated and point at the same angle towards an one point.

When rendered Maya software will create two sequences of images, one from each camera. It is later on in Post Production where I’ve overplayed both the images. Also images from the left camera have had green and blue channels removed from them, and the images from the right eye have had red channel removed.
Here are the results

A link to my personal website, Under “Stereo”, just use the keyboard left and right to change frames… Enjoy

oa-s139-04.sheridanc.on.ca/index.php

A Note on the 3D Vision Club Project

3dvisionclub — Fri, 18 Dec 2009 19:53:02 +0000

A Note on the 3D Vision Club Project

December 16, 2009 by chrisatimm

3D seems to be all the rage this moment. More movies, more 3D capable theatres, more games, and the first 3D capable television …

So it is definitely a good project subject.

There are a lot of different aspects to 3D vision. All our club members got involved in searching the web and other publications and we got an appointment with Mr. Song at s415 in the SCAET building. I put a summary of my understanding of what I found on the web and heard from Mr. Song in an email to the rest of the group. An email I copied lower down the blog.

My own particular interest goes to ’stereoscopy’, which basically is dedicating a separate image to each eye, taken with cameras separated at approximately eye distance between left and right eye. Blame it on my ViewMaster having being one of my favourite possessions as a kid.

I firmly believe that combining new technologies (better monitors, cameras, …) with older technology (optical) can still be worth our while.

Therefore I started experimenting with two web cams used simultaneously, creating two images on a monitor. The challenge is to create an optical system that allows you to look with one eye at the one picture, and the other at the other picture. I tried this with mirrors but haven’t been able so far to make something well enough aligned and stable enough to be used with real success.

The promise of a system like this is that the optical system is independent of the picture generation. So as better material becomes available (monitor resolution and size, camera resolution, remote controlled moving cameras, …) what you see gets better with the same optical set up.

Apart from this I also tried out polarized glasses in front of a projector and wearing polarized glasses. This did not work. I found out on the internet why not. Most projection screens mess up the polarization. It takes a special screen to ot mess up the polarization.

All great fun.

Chris

Dec 16th, 2009

3D Vision
10/27/2009
Meeting with Mr. Song, at Sheridan, S415

Mr. Song gave examples of different techniques:

1. stereoscopic images (example ViewMaster, late 19th century cards
with two pictures (left eye/right eye…))

Pros: simple, cheap;
Cons: no moving images, can only be viewed by one viewer;

2. holograms – used to be monochromatic, now full colour and high
resolution

Pros: high resolution, now in full colour, no special glasses
needed;
Cons: needs external light source on it, expensive and complicated
to produce;

3. multiple images broken apart and arranged in lines to compose a
picture seen through special screen. This technique is used in many
different ways:

a. printed material with plastic grooved lens (parallel lines)
attached to it (example of dog on notebook cover)(static image);

Pros: simple, cheap, no special glasses needed;
Cons: one viewer at a time, limited viewing angle;

b. plastic grooved lens in front of iPod (moving image, animation)
(example shown on Mr. Song’s iPod), no gap between iPod screen and
lens;

Pros: relatively simple and cheap material, no special glasses
needed;
Cons: limited viewing angle, one viewer at a time, lowered
resolution

c. sophisticated bigger lenses attached to computer monitors/TVs and
showing more than two views, with gap between screen and lens;;

Pros: wider viewing angle, no special glasses needed, more than one
viewer;
Cons: expensive screens, expensive and complicated production with
multiple cameras;

4. projected images with different colour filters or polarization
filters for each eye or synchronized shutter techniques by which the
viewer sees alternating images in rapid succession;

Pros: can be seen by many viewers simultaneously, great for special
effects;
Cons: coloured lenses do not allow for normal colours;
polarized lenses mean loss in luminosity;

Some of the points to note:

1. 3D content production is greatly helped by taking into account how
the human brain perceives 3D: changed focus (depth of field) and size
for different distances, shadows, straight lines seperating for
instance walls, ceilings and floors (perspective clues) …

2. Because most of these techniques are based on two or more images
being shown in the same space and in the same time as we perceive the
final composed image, resolution is typically divided by the number of
images shown simultaneously and refresh frequency needs to be a
multiple of the frequency typically used for non 3D imaging. For
instance the iPhone has a resolution of 320 x 480, which gets reduced
to 160 x 480 (no vertical duplication of image).

3. Several different aspects of 3D vision are used either seperately
or combined: the different viewpoint of left and right eye and the
different views a viewer expects when he/she moves. This also opens up
the possibility of simulated 3D where viewer position is tracked to
show different images on the screen (for example through the use of
sensors as found in the Wii controller or the small sensors Mr. Song
showed us).

Conclusion:

Most of the discussed techniques require substantial resources. The
cheapest to further experiment with may well be stereoscopic vision
(dual image) and simulated 3D (Wii controller).

Chris Rogiers – 10/28/2009

Interactive 360 Light Field Display

mfabricio — Fri, 18 Dec 2009 19:31:05 +0000

http://gl.ict.usc.edu/Research/3DDisplay/

Folks at the University of Southern California were able to create a real-time hologram. In my opinion is the best example I’ve seen so far. I didn’t understand much of the theory behind, but apparently there is a Anisotropic Spinning Mirror rotating at a high rate and an image of the real object is projected onto it from the top. Further information can be found on the link above.

The most interesting aspect of it is that there’s no need for goggles!Also, one can view the object in a 360 degrees range. I always wanted to have one and can’t wait to see this one available to the public. They have been using it for Teleconferencing.

by Fabricio.

Saving Prince Hal

mfabricio — Fri, 18 Dec 2009 19:20:59 +0000

I found this very interesting. In 1403 Prince Hal of England was in the battlefield and had lifted his visor perhaps to give an order or for ventilation and was wounded in the face by an arrow. He was saved by a London surgeon called Bradmore. You can read more in the link below.

Recently, The Digital Design Studio and the Scottish Medical Visualization Network were approached by Wild Dream Productions to assist in the production of a TV documentary series about medieval medicine for the History Channel. They replicated the surgery Prince Hal went through using their 3D equipment. I wasn’t able to found the video, but in the link below you can find more information about their amazing lab. The 3D models were very clear and sharp and one was able to zoom in and out to check on details.

http://www.rcpsg.ac.uk/hdrg/2006Nov3.htm

http://www.medicalvisualisation.co.uk/index.php?Itemid=17&id=2&layout=blog&option=com_content&view=category (Article at the bottom of the page)

by Fabricio.

3D vision the next stage

3dvisionclub — Fri, 18 Dec 2009 18:47:58 +0000

Ok… we finished with the research, the presentations and the showing of our examples in the Multimedia Pioneering class………… I think the next thing I would like to try is to bring the same technology tha Johnny Lee is using with the Wii to Flash, and in theory it shouldn’t be difficult, here are some of the steps we’ll need to follow:

1. Find or create the application for face tracking inside of Flash. I know there are plenty out there already, so we could just try those out and see which one is the best for this case. We need a face tracking application that works great not only in the x and y axis (up, down, left and right) but that can also detect when the face in the z axis ( when the face is closer to the monitor and when it is far away) so that we can really create the whole 3D effect.

2. We need to create some sort of 3D scene. I think Papervision3D or any of the 3D engines for flash out there can do the work just fine. We would need to create a room (can be just a grid) that vanishes as it gets closer to the vanishing point in the scene. We could put some targets in space and draw lines from the center of them to the vanishing point fading out as they get closer to the horizon line.

3. The first tricky thing woul be connecting the two together. I personally have never tried it and don’t know how hard it is… but I suppose it shouldn’t be that hard.

4. We would have to come up with some kind of formula or ratio as to how much does the camera on the 3D scene moves according to our head position. And this is key, because it gives the effect of stuff coming at you and popping out of the screen. If we create a square around the head in the head tracking app and mirror the movement of that square up, down, left, right, forward (square gets bigger) or backward(square gets smaller) and “attach” that movement to the camera then we’ll have a great 3D illusion on screen. =)

by Isaac Luy

Computer 3D – tricking the eye research

3dvisionclub — Fri, 18 Dec 2009 18:47:12 +0000

It’s been a while since my last blog on the 3D project…
but I rather write about stuff that matters than just blogging “for fun”

A couple of days ago I had a talk with Song at the Visualization Design Institute in Sheridan College (he has been of great help for all of us at the 3DVision Group)… and talking a bit about trying to implement the Wii head tracking project in Flash using the head tracking API, he made me realize that 3D in a 2D screen is a lot about implementing little tricks to make the brain think that he’s looking at 3D stuff…

So 3D is an illusion… (I guess we can say that in general not only in computer graphics) and after an interesting talk with Song, some of the tricks we can use to replicate that illusion are:

1. TRANSPARENCY: If you are working with line and dots going to a vanishing point a simple trick is to use transparency. Things that are closer to us seem more opaque/sharp and thing that move away start becoming transparent. If you have a line that comes straight into the user’s face make it so that the line is more opaque at the “front” and goes to transaprent as it gets closer to the vanishing point. I noticed that in the Wii project Jhonny Lee uses this trick for the lines behind the targets and it really works great. Jhonny Lee – 3D with the Wii

2. SHADOWS: A very important trick to simulate 3D. if you get your shadows right you can make any object look amazing in 3D… Our brain is used to interpret shadows in giving objects depth. So, you can draw a flat circle on the screen and just by applying a couple of shadows in the right places you get a perfect looking sphere. “Any object shadows itself”.

3. PARALLAX: If you have a camera moving though a “3D scene” a good trick is to remember that objects that are farther away from the camera move less than object that are closer to the camera. This is what people call Parallax. and there is a very simple example in wikipedia.

4. MOVEMENT OF THE SCENE: Moving the “3D scene” can accomplish the same effect as moving the camera, but when you are doing head tracking and 3D together, scene movement is another component that need to be taken into consideration because you have to come up with some equation (varies depending on the scene) of how much does the scene moves depending on the movement of the head. You are usually going to move the scene a percentage of the head movement distance. If you have the viewer initially looking at the scene right in the center and then he moves his/her head 10cm to the right then you are going to have to move the scene in the opposite direction a distance between 1 and 10cm (depending on the wanted effect) so that the brain of the viewer can interpret the head movement as actually looking into a 3D scene.

The next stage of the project is going to be trying to implement a head tracking application for flash, which shouldn’t be difficult since there are a lot of them already out there and there is an open API for that.

Here are some interesting links that Song gave me:

- OpenGL
- OpenCV
- GLUT

by Isaac Luy

3D vision example works!

3dvisionclub — Fri, 18 Dec 2009 18:44:08 +0000

Hi there!
Just wanted to share with you the fact that I got the Jhonny Lee 3D using the Wii remote [link] workig!
It is quite simple… I took me a little longer that I expected because I got a virus on my pc and had to re-image it and set everything up from scratch…. =S

But anyway… a little advise if you are going to try this yourself… remember to dowload and install the latest Direct X Runtime from Microsoft [link] on your PC. I spent a good hour trying to figure out why it wasn’t working when it should and realize that I had a really old version of the Direct X installed. [Maybe I need to play more games]

Now I’m of to trying to install a C Sharp compiler and try to change the content to something more “dinamic”… let’s see how hard it is to accomplish this… If you have any suggestions you are more than welcome to comment!

cheers!

by Isaac Luy

Exploring other 3D vision alternatives

3dvisionclub — Fri, 18 Dec 2009 18:43:14 +0000

ust a quick note:
last Tuesday I went with my fellow classmates to the VDI department in Sheridan to meet with a guy named Song.
As we got there we were greeted by this nice asian guy that welcomed us into their lab.
He seems really excited about the whole 3D vision experiments that have existed for a while now… he talked to us for about an hour about the different techniques, the different lenses, things that you have to take into consideration, holograms, he gave us some names and resources….
I didn’t think this was such a complex world… I guess we better start doing some serious research! get our hands dirty

by Isaac Luy

Connecting the wii Remote to my PC

3dvisionclub — Fri, 18 Dec 2009 18:42:28 +0000

As of last Wednesday I completed Phase two of my 3d vision project.
The Jhonny Lee stuff runs on my PC.
Make sure you have the Direct X thing installed on your PC before trying it out and getting an error.
Now I just have to take my wii to the lab and try the whole thing out.

————————————-

OK!…. I just did something I though was really hard to do…
and it turns out is the easiest thing in the world (probably most of you guys out there already know how)
I connected the wiiRemote to my PC!…
I used the BlueSoleil software… which is really easy to use! (http://www.bluesoleil.com/download/Detail.aspx?TID=26)
and I followed the instruction on (http://www.wiiprojects.org/bluetooth.html)
and that was it….
to be sure that it worked I used (http://onakasuita.org/wii/index-e.html)

And now I can control my PC cursor from the couch =)…

This is just the first step of a 3D project that we have on mind here at IMM in Sheridan… so, phase one acomplished and it was really easy… if you have any trouble setting this same thing up… drop me a line! =)

————————————

by Isaac Luy