remember those cheesy things from the 80''s(holigrams)? I was wondering if there was some method or way to do a holigram in OpenGL.

Draw the hologram as a quad. Use the stencil buffer to put whatever the hologram is of on the quad. Make sure it all has blending on so you can see through it. You can even make a scrolling/flash alpha map so it looks like the connection is breaking up.
EDIT: Err, if you don't want the style with the quad you can just play around with opacity and alpha maps. You could make an alpha map with straight lines across it and translate the texture matrix each frame, for example. To make a scrolling effect.

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MSN: nmaster42@hotmail.com, AIM: LockePick42, ICQ: 74128155
"It's all part of the conspiracy of conspirators conspiring to conspire their own conspiracies..."

[edited by - LockePick on December 19, 2002 1:26:38 AM]

I don''t think he means like a project image hologram, but one of those shiny ''animated'' trading cards from back in the day. Move the card, the light on it changes and the picture is doing something different.

Ah, I see I see. I thought he meant cheesy 80''s TV shows with holograms and stuff :D

Hmm, there''s problem some nifty multi-texturing functions you could use for that. I could think of a way to do it with the stencil as well (draw two models, adjust opacities depending on camera angle-to-surface normal) which would leave a texture unit open for multi-texturing an enviroment map to make it look shiny.

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MSN: nmaster42@hotmail.com, AIM: LockePick42, ICQ: 74128155
"It''s all part of the conspiracy of conspirators conspiring to conspire their own conspiracies..."

Alternatively, just do it the way the REAL holograms work.

/\/\/\/\/\/\ (supposed to be at 90 degrees) ... on the / ''s you put bits of one picture, on the \''s you put bits of the other, then depending on the angle to the camera it''ll show either one picture or the other.... just like how they work in real life.

Those things used to rule, nothing cheesy about ''em! *cracks open his frosties so he can get the "special edition" hologram card inside*

Just to throw another rivet into the works, he _may_ also mean the little shiny thing you get on credit cards.

An approximation of one of these could probably be done, but since our eyes give us a stereo view on the world, I don''t see a way to do this with a single viewpoint.

quote:

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Original post by Juicy
An approximation of one of these could probably be done, but since our eyes give us a stereo view on the world, I don''t see a way to do this with a single viewpoint.

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Solution: stereo imaging. Look up back/front left/right buffer for OpenGL. See: glDarwBuffer(), glGetBooleanv(GL_STEREO) to see if stereo imaging is supported.

Hope this helps,Crispy

quote:

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Original post by Crispy

quote:

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Original post by Juicy
An approximation of one of these could probably be done, but since our eyes give us a stereo view on the world, I don''t see a way to do this with a single viewpoint.

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Solution: stereo imaging. Look up back/front left/right buffer for OpenGL. See: glDarwBuffer(), glGetBooleanv(GL_STEREO) to see if stereo imaging is supported.

Hope this helps,Crispy

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That thing about seeing a different image based from the angle will be largely explained in tutorials that talk about impostors, just google for them (there is one on nVIDIA''s website, iirc).