Anaglyph (=red/cyan 3D-pics) of 3D-designs

[geert_2 557]

Okay guys, it's time to get your red/cyan 3D-glasses out!   :-)

I tried making a few anaglyphs (=red/cyan 3D-pictures) of a 3D-model. These 3D-images were hugely popular in the nineties, but I haven't seen much of them lately. They give a better understanding of the internal structures of a model, like watermarks; and give a better perspective and feel of depth. Also good for microscopy images of cells and fine structures, where the 3D-effect is important for understanding.

 

They are reasonably easy to create in a 3D-editor:

 

- In the 3D-editor, shift the model to the left of the screen, in perspective mode, by using the "Pan" function. This is the view that your right eye would see. Save this view as a picture, and name it "right-eye-view", or so. The 3D-editor should be in a real "architectural perspective" view mode, not a technical "ISO-perspective" with parallel lines but without perspective. It is the real perspective that makes this work.

- Shift the model to the right on the screen. This is what your left eye would see. Save this view as picture and name it "left-eye-view".

- Do not rotate the picture on-screen, only shift using the Pan-function.

- It is best if the background is pure white.

 

- The red glass is on the left, the blue glass is on the right (think of politics: red=left, blue=right). Actually, the "blue" glass should be a intense dark cyan, not real deep blue. And the red glass should be a deep pure red.

- Red text or images are invisible through the red glass, because everything is red anyways; you can't see the difference. Only cyan (the opposite color of red on the color circle) is visible as black through the red glass. So, we need the left-eye-view to have a cyan color, to be visible in the red glass.

- Idem for cyan: cyan images are invisible through the cyan glass. But red images show up as black. So we need the right-eye-view to be red on the screen, and appear black through the glass.

 

- In an image-editor capable of layer-editing (e.g. Photoshop, GIMP,...), load both images in different layers, in a new picture.

- Make the left-eye-view bright cyan, by setting the Green and Blue channel's output levels in the Levels-dialog to maximum, thus: R,G = 255 dec, or FF hex, or 100%, whatever notation your editor uses. Leave the Red channel untouched.

- Make the right-eye-view red, by setting the Red channel's output-level to maximum. Leave Green and Blue channels untouched.

 

- Set the top layer of both layers to "Multiply" mode, so the layer below shines through. This gives the composite red/cyan view.

- Now shift both images to the center of the picture, and correctly align them for a nice 3D-effect, when seen through the red/cyan glasses.

- If the areas that exactly overlap each other are in front of the model, the model will seem to sit behind the screen (see my examples below).

- If the areas that exactly overlap are in the back of the picture, the model will appear sit in front of the screen, and you need to focus in front.

- So you can move the model from behind the screen to in front of the screen, by shifting the red and cyan layers in respect to each other.

 

- It works best with monochrome images, but it also works with very desaturated colors. Bright colors do also work, but only if they are ca. 90° separated from red and cyan on the color circle, thus yellow-greenisch, and purple-blue. So, landscapes with fresh spring-green and with a desaturated cloudy sky also work.

- On a good screen and with good glasses, there should be not too much "halo" images, where the wrong color shines through the glasses.

- It works with renderings with and without black edge-lines, and to my surprise it also works in inverse images.

- You may need to lean a bit forward or backward (25...40cm?) to get the best effect.

 

See some of the tests:

 

Model behind the screen, opaque.

 

 

Model in front of the screen.

 

 

Model behind the screen, transparent.

 

 

Model behind the screen. This gives a good view of the internal watermarks and rulers, and of other openings.

 

 

Very pale model, in front of the screen. This works also, to my surprise.

 

 

Model in front of the screen.

 

 

Same model, but in inverse colors. This one is more prone to "ghosting".

 

This is just a technical model, a keychain of it. But for really artistic models like statues and buildings the effect should be way more impressive.

 

Edited April 3, 2019 by geert_2
Added pic of red-cyan glasses

[owen 19]

I've done a lot of stuff in 3D, photos etc. and these are done beautifully. Very clear and easy on the eye. Sure does give a better view of the model. Well done.

[Enigma_M4 119]

Great work! Fortunately my 3D-Glasses lie ready to use besides my keyboard (old Red/Green type, but works perfectly with your pics)