Camera Settings to render a still Image ?

[Interlink]

I'm trying to render a still Image (later a Video) with "Cinema 4D" (a 3D modeling, animation and rendering application).
At that early point I will use the OR just as a viewer, I will later enter into programming.

Please correct me if I got it wrong, here is my plan:
The OR has a native Resolution of 1280x800, so I part the Image into a left and right Part of each 640x800.
I place a Camera in the Scene and render the left Image, then I copy that Camera and move it parallel 3 inches to the right and render the right Image.
Glued together and on fullscreen, there it is, but the 3D is wrong.

(I read the SDK Doc but till I get the Math it will take a long time... but I will.)

What Camera Setting does it need ?
Field of View Horizontal,
Field of View Vertical,
Projection (Perspective/Parallel),
Focal Length ?

Did I miss an important Setting ?

[3DArtist]

Can you give a more detialled description in how far the 3D is wrong?

To test the depth of an image you can combine the two different renderings in photoshop to an anaglyph image and check it with an anaglyph (e.g. red/cyan) glass.
Just google for an anaglyph tutorial to find a workflow.

If the 3d seems correct in PS, then it isn't the 3d-Setting that's wrong.

[Interlink]

The Center of the Image is at the right place, but everything else is wrong.
The default camera settings produces a flat image, but for the Lenses of the OR it must be distorted/warped.
Distorted Image + Lenses = Wide-angle View in OR.
(I don't have Photoshop.)

The pincushion distortion (not sure?) is missing, but I can't get it by Try&Error with this pattern:

Or can't this made by Field of View Settings ?

[jherico]

"Interlink" wrote:
Or can't this made by Field of View Settings ?

No, you cannot implement the distortion by altering the field of view. The distortion effect of the lenses is a non-linear function, meaning straight lines in an image viewed through the lenses will be curved. You therefore need to curve distort the image so that it's straight lines are curved in the opposite direction, so that when these lines are viewed through the lenses they appears straight. No amount of fiddling with the FOV will ever produce curved lines.

If you want to take a camera image and display it on the Rift properly, you either need to warp the image in software after the fact, or you need to take it with a fish-eye lens, ideally with the exact inverse distortion that the Rift lenses apply. Not sure how you'd go about getting such a an exact match, although I've found that the fish-eye lenses designed for magnetic attachment to the iPhone are a very close match. Good enough for government work anyway. 🙂

[Interlink]

Too bad, thank you all for the answers, so I have to do the math. (Doh)

[bubimude]

Hey Interlink, I've been experimenting with a c4d setup myself. First off, the real problem is that cinema 4d doesn't have a spherical render mode. You can achieve this by rendering through a reflective sphere, but it's not the ideal renderer for using with the oculus. The reason you want a spherical render is, you don't want any lens distortion, and you basically want a render that you can map back onto a dome like screen when viewing in oculus. As for the camera settings, you basically just have to match your virtual "screen size" to the camera settings you used to render. If you render with an fov of 195 degrees for example, then you need to map that back onto a dome that has the same degrees. I use VR player, which lets you do this manually. You can even important custom geometry to use as a screen. The good thing about VR player too is that it adds the distortion (not the c4d camera distortion, it adds the proper distortion for viewing with the oculus).
I'm working on a rig right now that uses 50 cameras to create a 180 degree pre rendered scene out of cinema. I'll be posting soon hopefully with my findings.

[abuVR]

hello together there is a spherical camera you can get at cineversity CV-VrCam...
greets