Celtic Knot - The Stereogram Version

[Soquili]

Hi Gary,

I like this very much. It looks much better on my new LCD monitor at home than on the CRT monitor here at work though.

Mike - it can't be because you wear glasses. I wear tri-focals and I see them without any problem.

Soquili

[TimS]

Count me in as one of the interested.
tim

[gwpriester]

Mike and all. I only asked about glasses because a friend of mine who wears glasses said he had trouble seeing the images with his glasses and my wife is not able to see the images when she wears her glasses.

Attached is the depth map image, the image used by the software to determine the depth of the hidden image. From white, which comes forward the most, to black, which recedes the most, there are 254 shade of gray which are translated as layers of depth.

The first image shows the depth map image with red outlines to show the individual components. The white area will appear to be in front of the darker areas which will recede.

To add some shape to the individual pieces, I created a duplicate of the knot and combined shapes > add shapes to make one shape. I applied a contour to this shape and created a bitmap with a transparent background. I cut out a section of a duplicate bitmap which I used to replicate the over and under.

The bitmap was placed over the depth map image and Stained Glass transparenct applied. The bitmap added a bit of shape to the knot. Without this the over and under would look very flat and ribbon like.

I use this technique a lot to add shape and more depth to the hidden image.

Gary

Gary Priester

Moderator Person


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www.gwpriester.com </a>


<a href="http://www.xaraxone.com">
The Xara Xone </a>

[Ross Macintosh]

joroho - maybe you got hit in the head with a baseball??

I was one of those people who thought I'd never be able to see the 3d effect. I tried many times over the years without success -- until...

eventually I took seriously the advice to put my nose on the monitor & slowly pull my head back. Now I see them fine. When I now put my nose (average sized) right up to the monitor I don't pull away until my eyes are seeing the pattern of the monitor's "screen" -- The image at this close seems to be kind-a irrelavant as all I see of it is a blurry mash of colours. As I pull away slowly the virtual 3d object comes into focus and that's when I exclaim "Wow!"

Regards, Ross

<a href=http://www.designstop.com/>DesignStop.Com</a>

[gwpriester]

Aside from Ross's suggestion (be careful not to get a nose print on your screen) here is another method.

The biggest trick is RELAX. This is not a pass or fail contest.

I like to pretend I am looking at something on the wall that is behind the image. In essence when you see the hidden stereogram image your eyes are focussing in the distance so pretending you are looking beyond the image can help.

Looking at a stereogram is a good way to gets your eyes to focus on the middle distance. There was a fellow a few years ago who was going to make a changing stereogram screen saver that would come up at user selected intervals so you could take an eye break and focus beyond the screen.

Gary

Gary Priester

Moderator Person


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<a href="http://www.xaraxone.com">
The Xara Xone </a>

[simsmj]

Gary, I downloaded Stereogram Explorer, and have started playing with it. I notice that it offers the option of converging or diverging, with diverging being the default. I have always had trouble with the diverging kind of stereogram, but can see the converging kind effortlessly. Perhaps if you could post a converging version of your knot it may be that others could see it who couldn't otherwise.

The trick for converging grams is to slightly cross ones eyes, so that the image overlaps itself. It usually possible to see a repeating pattern, so try to make two adjacent patterns overlap on top of each other. At that point the 3d image should become apparent.

I tried using the depth map you posted in Stereogram Explorer as a converging image and could see the knot properly for the first time, and very effective it is too. Even the depth map looks the business!

Mike


Just chugging away...
Mike Sims

[Su Lawrence]

... who couldn't see stereograms at all. But a while ago when you posted your leprechaun stereogram I had another go. I still couldn't see the leprechaun's hat but on the XaraXone there are four stereograms (think it was from this January's tutorial?) which are of a round hole in a flat surface with a cone shape coming through.

I used a small and dimmed torch (easier to focus on a dimmed light without getting spots before your eyes!) and shone it on the monitor and then moved it outwards from the monitor whilst focusing on the light and suddenly for the first time I saw the 3D image as mentioned above, very cool! Although I must say I do generally tend to end up with a headache so I don't look at them for too long!

I still however, can't quite make out this stereogram though ... sigh.

Regards

Su

[This message was edited by Su Lawrence on April 12, 2003 at 11:48.]

[Acorn]

I could not resist the urge to take the Celtic Knot Guest Tutorial for this month and try to recreate it as a 3D stereogram.

The actual image is 10" x 8" which is a little large to post here, but the depth is amazing at that size.

Gary, do you think you could recreate the Celtic Knot with the graduate fill line approach?
I am curious if it will be crisper.

Acorn

[gwpriester]

It would need to be a series of Art Brush effects. Not sure, I'll have to try.

I have been experimenting with different kinds of fills with some interesting results.

[Egg Bramhill]

It's an interesting way to create celtic knots. It can do your head in but so can creating them by the normal method I use.

There is an error in the under/over in this file but I'm not of the mood to fix it just now.