CompuServe Thread

#Stereo in 3DS

5 messages in this thread
#37042From: Alexander MathysMar 11, 1993 7:16 AM
Jason: About "experimenting" with stereo-pairs: I used to do quiet a lot of normal stereo camera work…..some hints: – If the camera lenses are parallel: the objects appear in front of your screen! You have to converge the cameras at the 'far point': all object appear then behind the screen (like looking into a theater setting). – The scene boundaries represent in stereo this kind of 'virtual window'. That means an object which doesn't fit in the scene and is placed IN FRONT of the virtual window is cut at the picture edge, which gives you a disturbing 'visual unlogic' situation. – In 3DS you can easily find the place where the 'virtual window' will be: if you switch on the camera cones, the stereo-window is in the plane where the two cones intersect (in top view). – BTW: the distance of the two cameras (the two eyes) is most important. As a rule: imagine the scale of a human figure in the setting and the relative distance of his eyes (ca. 2.5 inches). If you set the cameras more appart, you'll get what's called 'giantism' (the relativ human figure would be a giant; the 3D scene appears like a small model setting). The other way round (narrow camera distance) you'll get a so called 'lilliputism' setting. – For a very general rule: Try setting the cameras about 1/30 of the distance to the 'near point' (=the nearest object to appear in the scene). This will give you a good, not 'overdone' angle. – About the 'virtual window': you can have objects leaping out of the window (=being nearer to the cameras than the 'window plane'), but as mentioned these objects shouldn't intersect the picture edge. (…an effect often used in the stereo movies of the 50's….). Just two days ago I tried some 3DS stereo stills, changed the colors to the well known red/green afterwards and combined them to a single picture to view with the simple red/green glases (worked quiet well….a good green/blue color is always difficult to find). Hope this helps a bit…..(good stereo is not that easy and has certain rules….) I could name you some good books about the theme (dealing with general rules and photographie), let me know if you need some more information. …………………………………………..Alexander.
#37156From: Jason E. KirtlandMar 12, 1993 12:14 AM
Thanks for the info. I'm intregued about the red/green glasses solution. How did you go about changing the colors appropriately afterward? Does this approach limit you in the types of materials you can use in designing the scene? -Jason Kirtland
#37171From: Alexander MathysMar 12, 1993 8:35 AM
Jason: Have a look at the 'pen-3d.gif' sample, I uploaded it to the 'what's new' section…should be there in a day. (I hope that worked well….). There you see the colors, the described 'virtual window',… (the end of the pen is leaping out of the image: move a cursor over the picture while watching…you'll see). Hope you have some red/green stereo glasses! About changing the colors: make the two 'eye-views' in 3DS as MONO TIF's. Then you have to use a software like Picture Publisher, Photostyler, Photoshop, etc. Convert the greyscale images in RGB true color. In the left image, take out all blue and green components (and tune it to a higher contrast). In the right image, take out the red (gives you a red/blue image), leave the contrast as it is. Then you have to merge the pictures: Make shure the software a) can do this and b) does it by color _addition_. The resulting picture should be quiet good in the colors. If 'ghost images' occur at the edges, try adjusting the contrast/brightness of the images first (it's nearly impossible to take out all 'ghosting' by color tuning). Hope you like the example-gif…..let me know. ……….Alexander. PS:I like to figure out how to animate the entire 'double-camera' thing, but I'm quiet new in the 3DS field and till now did stills only. Any idea how to animate this kind of real 3D ???
#37189From: yann bertaudMar 12, 1993 11:34 AM
Theoretically, you could render the animation and use CLAMP IXP in the video post to achieve the proper results. It's not something I have tried to do, but it could be very interesting. Unfortunately I am partially blind out of one eye so the stereoscopic stuff doesn't work for me, I feel like I am missing out on something really cool. Oh well, that's life. Yann Bertaud – I.D.L. Autodesk.
#37237From: Alexander MathysMar 13, 1993 4:47 AM
Yann: Thanks for your hint…I have not explored 3DS as far as 'video post' it's all quiet new for me, working step by step every day. But I have to say: it's great. I guess it is the fascination to have the possibility to virtually build everything you can imagine and to bring it to a form that makes it easy to think the thing is real. As an architect, I'm impressed that the software really gives me the possibility to control and 'feel' the spacial environment I'm designing. Now, the 'stereo-option' just takes the result one step further to 'reality'. BTW medical gurus say 6% of human beings are not able to see the environment properly in a stereoscopic way by different reasons. Thanks again for your hint, i'll try this as soon as I _can_… Alexander.