What's the purpose of 3D ILDA files??

[carmangary]

If scanners only have X and Y, what is the purpose of ILDA files that have points with X, Y, & Z?

[buffo]

It doesn't have anything to do with the scanners, but rather with the information contained inside the file. 3D ILDA files are complete 3D models (that is, they contain depth information, just like CAD files) and thus they can be rotated to show the back (hidden) side of the object.

Think of a 2D animation vs a 3D animation. If you take a 2D object and rotate it on the x or y axis, the image will get thinner and thinner until it becomes a single line (either horizontal or vertical). Now, do the same thing with a 3D object and you'll see that the object stays the same size, and as it turns you can see other parts that were originally hidden from view.

A 3D ILDA file, when animated, will look more realistic than a 2D file, because rotation about the x and y axis will not distort the image like it would with a 2D file. (Rotation about the Z axis will look the same for both files.) Basically 3D ILDA files are more detailed models of the objects they display, whereas standard 2D ILDA files are more like drawings of objects; drawings that can't be manipulated very much without introducing lots of distortion in the image.

Note that not all laser display software supports 3D ILDA files.

Adam

[mixedgas]

You can produce a 3D object in wireframe form and have a clipping plane in software about halfway back through the z axis (depth) of the 3D image, things behind the clipping plane are blanked and thus you can see a much better detailed picture of a object, esepcially as you rotate it during a show.
(or even fly through it if the image is say a tunnel) A few older laser systems can actually generate a laser image for each eye just like the old 3D movies, wearing goggles of course. Take some copper wire, make yourself a six sided outline of a cube, imagine each wire in the cube as a laser vector, you'll get the idea. If you project the cube as is,on a 2D system, it looks like mush, if you have the computer do some math and creative blanking, its still a XY scan, but shows perspective to the brain. It also allows for what is called hidden line removal, I have one older show where a 2D space shuttle flys around the 2D earth, in a circle, never crossing the earth cause it would look jumbled. With hidden line, in another show the 3D shuttle flys around the equator and the parts of the earth "behind"the 3D shuttle image disappear like they would if a real solid shuttle blocked your view.

a example is on Pangolins web site

3D:
http://www.pangolin.com/LD2000/lc-max_overview.htm
The space station rotating about half way down is a 3D frame
watch the yellow habitat module in front of the artifical gravity ring, see how the ring is hidden by the yellow object until it rotates into view?

2D:
the shark
http://www.pangolin.com/aud_shark.htm

or the
good examples on elm's page

http://elm-chan.org/works/vlp/report_e.html

Steve



steve

[carmangary]

Thanks for the explanation. So basically, you could have a animation using 3d frames and then rotate around the animation to see all sides?

Do you have a sample 3D file that I could have? I'd like to make my ILDA viewer have the capability to view all sides of a 3D file. That would be pretty cool.

[DZ]

Thanks for the explanation. So basically, you could have a animation using 3d frames and then rotate around the animation to see all sides?

Do you have a sample 3D file that I could have? I'd like to make my ILDA viewer have the capability to view all sides of a 3D file. That would be pretty cool.

Regarding the above comment with link to the Pangolin's LCmax with video, that is not a true 3d frame, it is more of a 3d animation rendered in 3d Studio Max, then ported to Pangolin as a series of frames that appear 3d as it is animated. A true 3d frame doesn't really need to be apart of an animation. Attached are two examples of true 3d frames I made several years ago, anyone is welcome to use them. In Pangolin, you can use a 3d frame and manipulate it in many ways in Showtime, all with just using one frame instead of a series of frames. I'm in no way trying to knock LCmax, it is THE way to go to make laser shows. Just trying to give a better visual of what a true 3d frame is and how it can be used.

David

[carmangary]

Thank you much for posting the files. I'm looking forward to playing with them.

[Yag]

Rather grainy video of a low res 3D box rotating amongst the daffodils!



I seem to remember that's one of the sample shows that comes with Alphalite.

[Dr Laser]

The purpose of 3d ild is simple.
To do rotation of an 3D object in 2D you will need about 50-360 frames.
To do rotation of an 3D object in 3D you need only 1 frame and few commands to make it spin in any direction you want. Saves space and power.