TV screen refraction question

[someawfulbridge]

A couple of prelim questions for a project I'm going to be fooling around with involving a tv showing images. I understand how to apply a video/image sequence as a decal, so that's not my question.

 

I'm looking for a very refractive screen, more refractive than realistic, so the "projection" distorts as the screen rotates. Do I want to:

--make a screen with transparent/refractive materials and place it in front of a flat patch with the video decal?

--make a screen and apply the decal to the "back" of the screen?

 

Also, how is refraction calculated? Would I want just a one-sided (2-dimensional), one-patch screen (well, it'd be a couple of patches to accommodate the curvature, but it would have no depth), or an actual 3-D screen, with a front and back and implied material within?

 

I hope this isn't too lazy to ask--I'm fooling around with it a bit already, but if I can get a little ahead in the testing process, I'll be doing less whistling in the dark. It will be more like whistling in the dim.

 

Cheers--

Mark

[heyvern]

Well... the "refraction" of the television is really the curvature of the screen. The image is projected onto the powdered surface of the back of the glass. The refraction would only be from the thickness of that glass. I would experiment with this using a simple image decal to see the results. Refraction in AM doesn't always behave exactly the way it would in the "real" world. Even small amounts could produce extreme results.

 

Another key to make it look real is to get the glare and reflection on the surface of the glass OVER the projected tv image. Ironic that new tv's avoid all these problems. Probably been years since you could even buy a "curved" screen with glare issues.

 

My thought would be to decal the back of the glass "thickness" or decal a matching surface exactly behind the glass. If you want exaggerated distortion make the tv screen really curved. I would use thickness on the glass. I did this with plastic doors on my "Wonder Womb" image contest entry. It worked out great.

 

http://www.hash.com/imagecontest/Feb05/04.jpg

 

The plastic doors have refraction and a teeny bit of density which gives it a slightly cloudy look. Plus some specular and a bit of reflection. You might even be able to put a bright light behind the glass to show through the projection decal to create that flickering tv image... depends how real you want it.

 

All of this will probably require raytraced lights to work.

 

-vern

[jon]

tvs and other displays pretty much always cast their images on their surface, so there's no refraction to speak of.

 

why don't just just curve the surface of the display area?

 

if you really want to use refraction, then you'll need a transparent surface with the refraction setting -- the 'lens' -- with the display contents behind it.

 

-jon

[robcat2075]

I can't quite imagine the effect you're going for.

 

The glass in CRT screens is of such uniform thinness that refraction is a non-issue in real life.

 

What is the dramatic intent of this effect?