Hi all, I’m new to the community. Just recently tried Blender and it’s kind of interesting to me as a hobby. 
Well I am wondering is that possible to project 3D image of a model in Blender to a screen using 2 projectors and a shutter glass. And manipulation can be done using the projected 3D image on the screen. I was wondering mayb 2 cameras can be used in Blender but how do I project the image from each camera to the projectors?
Well, I’m not good with language but any help would be appreciated.
um just put the video on a transparent plane. :o
Hi !
I’m making stereoscopic photography for many years, and I have tried most of the technics in this domain. I may help you, but I need to know some informations :
1 - Do you want to display still pictures or 3D videos ?
2 - What do you mean by shutter glass ?
Do you mean shutter glasses ? (spectacles) or an oscillating mirror put in front of the projector ?
Shutter glasses are mainly of 3 types : LCD glasses, PZLT glasses (Piezo Light Transmitter), electromagnetic vibrating shutters.
PZLT cells are experimental and very difficult to find. LCD glasses were available from Hitachi some years ago and very expensives. Electromagnetic shutters are very annoying, heavy and noisy.
The simplest solution (but not practical) for projection if you want to use LCD glasses is a rotating shutter.
You must print your images on a high quality transparent film, and make slides for the projectors.
The projectors must be placed one over the other. Between the two projectors, you will need to add a flat box with an electric motor inside. this motor will drive a large disk (strong paper card or plastic wel equilibrated) with holes (the shutter) The holes are set in order to mask one lens when the other is opened.
If you make two crowns of holes, and the holes on the external ring less spaced, you will even be able to see the image on the screen in 3D directly through the disk without glasses ! But do not put your nose in the rotating weel !
This mecanical solution is heavy, though, and the best solution is not mechanical: it uses polarising filters on the projectors, and glasses with polarising filters too.
The 2 filters must have their polarising planes at 45 degrees right and 45 degrees left for the glasses and the same port the projectors.
The images must be superposed on a metallic (metallised) screen. This is compulsary to keep the polarisation of the right and the left beam.
Half of the light energy is lost in the filters, and powerfull slide projectors are needed (250W each generally).
If you want to see movies in 3D, there is also an other method. This method works only for travelling (linear or circulars). this means that you will need to create your videos thinking of that constraint.
This method is based on the Pulfritch effect. The eyes don’t send the nervous signal at the same time if they are not lit with equal energy.
The eye which receive less light sent its signal later. This means that if you are wearing glasses (for example sun glasses) with a different grey level, your brain will not see a moving object at the same place from the right ant from the left eye.
This is reversed stereoscopy. The brain can’t treat this information, and converts the angles in order to show you an understandable picture in which the relief is reconstructed. This phenomenon works only if the displacement of the object is in the right direction, related to the eyes illumination. If the dark glass is not at the good place, the relief is inverted, and you will get a strange feelin when an object moves behind an other, because closest objects seems far and the opposite…
You can use the pulfritch effect on a computer screen or a TV screen… there is no need to use projectors and to make slides.
You can even chexk the method while watching ordinary programs on your TV. The effect will be maximum for some travellings.
Try with old sun glasses (remove one glass) . Using glasses with one glass only works fine, but two glasses with different grey will give you a much natural feeling.
Try an tell me !
Philippe.
Hi thanks for the feedback and help guys.
Well I actually meant shutter glasses. But now that I know it’s not really the method that I would wanna use. First of all it’s kind of expensive for me as a student.
Actually what I meant in my first post was I wish to project what’s on my computer screen (Blender) or only the model (in Blender) to a screen on the wall so that more people can view it at the same time. I’ve found some scripts which would export images from 2 cameras (2 different angles) but I do not think that’s what would work for me as I do not wanna project still pictures but an object which can be viewed from different angles with the control of a mouse. So I guess the Pulfritch effect method would work better for me.
Hope to get more detail on the Pulfritch effect method. Thanks a lot
Hi !
The Pulfritch method is based on the movement, so, you can’t see any relief until the object doesn’t move, so, rotating the object with a mouse is not suitable.
One of my movies is good enought to be seen in Pulfritch effect :
Download the Toolbox movie on my website, in the MOVIES section.
It shows a rotating toolbox. If you haven’t yet some grey glasses (with one or 2 glasses) you can take a small paper card and make a pinhole in it.
Play the movie in full screen mode and place the pin hole in front of your right eye and look at the movie (with the 2 eyes opened, obviously !).
Some people said they didn’t see the relief… they were looking with one eye !
You should see the relief.
Tell me.
Thanks a lot for the information. I’ve visited your site, impressive work. Well done
Thanks a million.
Thanks!
Did you achieve to see some relief on the toolbox, or on a TV program with the Pulfrich effect ?
Philippe.