Home Forums Mistika VR Have tips for shot with close subjects and large depth differences?

This topic contains 7 replies, has 2 voices, and was last updated by  don 1 month, 2 weeks ago.

  • Creator
    Topic
  • #38490

    don
    Participant

    Is it possible to stitch this shot in Mistika VR? (See picture below.) Have you successfully stitched a difficult shot like this?

    Shot in a 25′ x 15′ room. The woman on the right was 1.3m from the Ozo camera (we also shot a version with the Jaunt). The man on the left enters and exits from the upstage door. The camera was next to the table.

    Mistika_rough_stitch_Ozo_2000x1003

    This is my best stitch in Mistika VR, without using Optical Flow. After loading the Ozo preset, I started by centering the images. The Improve tools didn’t work (they only made the alignment worse), so I adjusted each camera manually.

    This is too rough an alignment for Optical Flow to work with: it makes huge artifacts.

    (I’d previously composited out the tripod and other gear in Nuke. We shot a still plate of the table so that we could comp it in after the stitch, because it is within the minimum distance of the cameras).

    It’s a tough shot to stitch: the parallax differences are significant. Any tips?

    Don

Viewing 7 replies - 1 through 7 (of 7 total)
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  • #38502

    Rocío Del Pino
    Keymaster

    Hi Don,

    Thanks for sharing this issue in this Forum. I am working in a project with Ozo camera right now. Firstly, the preset in Mistika is coming with Stitch Feather in 100%. I am working in Stereo and to avoid occlusion objects in parts of the image with motion, I had to decrease to 50% this paramater. Even in your project without OF, increasing the Stitch Feather should works properly. In case you modify this parameter and you do not get the best result, I invite you to send me a frame of every single camera for testing and see if I can help you.

    Looking forward hearing from you!

    Best,

    .ro

    #38550

    don
    Participant

    Thank you, Rocío. I will try your suggestion next week and accept your kind invitation if necessary. Have a good weekend in the meantime!

     

    Don

    http://www.donstarnes.com

    #38976

    don
    Participant

    Rocío,

    I could not improve my stitch by changing the Stitch Feather. I also tried further adjustments on some of the cameras, but the alignment is still not close enough to prevent lots of artifacts when using Optical Flow.

    Can you give it a try? One frame for each of the cameras is in the zip file at:

    https://drive.google.com/file/d/1w97c78hNTwr8N65_Y3fSd0jyakqnrHQK/view?usp=sharing

    Can you export a preset for your result and attach it?

    Thank you in advance for your generous interest, Rocio.

    don@donstarnes.com

    #39037

    Rocío Del Pino
    Keymaster

    Hi Don,

    I have tried your footage and I have created a preset with OF Off with Stitch Feather 50%. Here it is how it works in my test:

    Ozo_forums_OF_OFF_000000

    After modifying the position improving Offset and angles, I just have added 1 edge point in camera #5 (in the ceiling) because OF did not work properly. If you turn on OF with Stitch Feather 50%, you would not see occlusion objects and the result will be like the next image:

    Ozo_forums_OF_000000

    I hope it helps!

    .ro

     

    #39108

    don
    Participant

    Thank you, Rocio, for your time and efforts. I didn’t see the preset uploaded with your post. Can you export it and post it here?

    Also: do you think that it is possible to stitch this in Mistika VR without the ghosting and optical flow errors shown in your second example?

    Don

    #39128

    Rocío Del Pino
    Keymaster

    OZO_forums

    Hi Don,

    I have seen your email via support asking the same issue. I will answer here and this maybe will help to other users. First of all, sorry for do not attach the preset. I thougth I did it but, nop ;( Ghosting can easily removed adding some edges point. If you increase the Stitch Feather with OF ON, you will need to use more edge points. In my last job with Ozo I found a perfect combination between Feather with OF and edge points. The attached preset show you how to fix it in the ceiling. Following that example you can continue adding some more. When adding an edge point Stereo, you have to select the Left camera and then place it where you find some gosthing. It is a very detailed job, but I am afraid we cannot get the best out of this rig.

    Best,

    .ro

    (The forum does not allow attach unzipped files…. that’s the reason I could not attach the preset. I am sorry)

    i

    Attachments:
    #39282

    don
    Participant

    Success! Thank you for your suggestions.

    8.8.4 was the main difference: its Improve tools worked perfectly with my shot. This meant that Optical Flow worked much better. Then, with a number of edge points, I was able to remove the remaining artifacts.

    The Ozo doesn’t doesn’t have much coverage at -180°, so I was unable to fix convergence errors (in the ceiling and baseboard) there. A feather of less than 70 exposes the gap in the Ozo’s rear cameras; I set the feather at 70 (the edge of that gap) to minimize overall ghosting. (I plan to paint out the remaining errors there in Nuke.)

    I found that I had to use left and right edge points in the ceiling and nearby table, as stereo edge points didn’t seem to work there (it appears that Mistika doesn’t make stereo above and below with the Ozo.) So: Mistika will work with my project! I’m grateful for your advice. Thank you again.

    Don

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