Aligning 3D pictures

[crunchy]

I tried to make 3D pictures by using "Calculate left eye image". However, I am not very happy with results. Sometimes left and right pictures are (vertically) well aligned and sometimes not. One example of bad aligning is the picture below. Am I doing something wrong?

[dddphoto]

Hello crunchy,

I create a stereo version of almost all my mandelbulb3d images. You can see my images on deviantart here http://dddphoto.deviantart.com/gallery/36006115. I am also a very experienced 3D photographer. I have two suggestions for you:

1) Do not use the "Calculate left eye image", but instead do it manually. To do this first render your left image as usual. Then make sure you have the boxed checked "fixed zoom and steps" in the bottom right of the 3D navi screen. Set your "Sliding+Walking Step" to 5. Now side step to the right one or two steps (this depends on the render and how far you are from the closest object and how far infinity goes). Now render the right image. One thing to consider is that some image area will be lost when you align the stereo pair so make your image a bit wider to compensate. Occasionally you will create an image that just doesn't work in stereo. I do not know why, but it just happens.

2) Use the free program Stereo Photo Maker http://stereo.jpn.org/eng/stphmkr/ to align your stereo pairs. This is the greatest stereo program ever made and will do amazing things. You can output into almost any format possible from full color anaglyph to side by side to over/under to 3D TV and 3D Phones to interlaced to .....

If you need any more help or suggestions please just ask.

[dddphoto]

Hello again,L

I just ran your image through SPM and here is what it needed to be aligned. Remember that this is based on the small image size you posted.

Rotation - Left 0 degrees, Right 0 degrees
Size - Left -1.2%, Right +1.2%
Vertical Perspective - Left +0.9 degrees, Right +0.3 degrees
Horizontal Perspective - Left +0.1 degrees, Right -1.0 degrees
Vertical Adjustment - 0 pixels
Horizontal Adjustment - 21 pixels

As you can see the biggest problem here was that your left and right images were different sizes. The auto movement of the program must have moved you closer or farther away when it did the second render.

Hope that helps.

[crunchy]

Thank you very much, David!

I will try doing the same procedure as you mentioned and I hope that after that I won't need SPM (except for horizontal adjustment, of course). Namely, making 3D video is more problematic, since each frame might require (different) adjustments.

Best wishes to ID,

Damir

p.s. Don't forget to click "Rect. lense" in 3D Navi ("rectilinear lenses" in camera). This option, when moving the picture, will (in most cases, but not always) preserve vertical positions of objects. If anybody knows even better way of making 3D pairs, let me/us know.

[crunchy]

Don't forget to click both "Rect. lense" AND "Fixed zoom and steps" in 3D Navi ("rectilinear lenses" in camera). This option, when moving the picture, might preserve vertical positions of objects. Jesse, do you know any shorter/simpler way how to achieve this (instead of clicking "Calculate left eye image", which, apparently, does not work properly for creating stereoscopic pairs)?

[Jesse]

Don't forget to click both "Rect. lense" AND "Fixed zoom and steps" in 3D Navi ("rectilinear lenses" in camera). This option, when moving the picture, might preserve vertical positions of objects. Jesse, do you know any shorter/simpler way how to achieve this (instead of clicking "Calculate left eye image", which, apparently, does not work properly for creating stereoscopic pairs)?

The left-eye image is a compromise to use the default pic as right one (but it is centered actually), so you get a little offset dependend on the stereo settings.  This explains the observations, there is no vertical movement but because of the different distances one object can appear bigger.
It is not diffcult to make more buttons for true left and right-eye image calculations and to adjust it for animations, wait for the next update.

[crunchy]

Jesse, this would be great! Thank you very much!

[crunchy]

Hi Jesse,

I have tried the new version. However, the pictures are still not aligned when using right and left buttons, as can be seen on spin_test.jpg.

Have you parallely moved the "camera" as shown in stereo_cameras.gif (the cameras should never toe-in!)? Namely only parallel change of the camera position will allow perfect 3D picture without veritical misalignment.
Of course, in this case the stereo window will be at infinity. In order to bring stereo window closer, one will have to cut left part of the left picture (several pixels wide) and right part on the right picture. This would, however, reduce desired horizontal resolution. Therefore, higher horizontal resolution (than prescribed) should be used before cutting so as to achieve the desired final resolution after croping the pictures. I might help you in calculations if needed.

There are some more comments:
- Stereo parameters are not saved when applying Save complete M3I ("save parameters only" option saves them, by the way).
- When having an object and clicking "calculate left eye image" and then "calculate right eye image", the object moves quite differently from the case when first clicking "calculate right eye image" and then "calculate left eye image". I would expect that left or right picture should always be at the same positions (same move from the initial/central position).
- In my opinion it would be better if parameters in the upper right corner (X mid, Ymid, ... ) would not change when calculating left and right images. Namely, left and right views are used only for making stereoscopic pair. I wanted to say that the actual parameters are changed when calculating left and right views, but the central viewing point should remain the same (all the parameters). Also, if repeating clicking "calculate left eye image", the view should not change at all, because it is "tight" to the same central position (similarly for the right one).
If the user wants to move the object, he/she should do that by changing central position (calculate 3D button) and not by calculation of stereoscopic views.

[Rathinagiri]

I do create stereo images using the method described by David. I use this method even in Chaoscope, Chaospro, Apophysis also.

[Boya]

Hi.
I do a lot of stereoscopic rendering these days, and experienced the same problems as Cruncy, although I feel I am getting somewhat less disparity problems than with v1.7.9.3
If you need parameters I can post, but I was waiting for the new update, as I saw Jesse knows some of the issues, especially concerning animation.

I just wanted to pose another stereo Q:
Stereo Base or IOD (interoccular distance) are the terms most used to describe the distance between the cameras in most other stereoscopic software, and in real life 3D camera setting.

I guess it is reflected in the three stereoscopic options provided, but would it not be usefull to bring this variable into the software?

Chers, Boya

[Rathinagiri]

Valid point Boya.