• Subscribe

    Subscribe to This Week In Panospace by eMail.
    Subscribe in a reader
  • License

    Creative Commons License
    This work is © 2008-2012
    by Yuval Levy
    and licensed under a
    Creative Commons License.
  • Entries

    April 2009
    M T W T F S S
    « Mar   May »
     12345
    6789101112
    13141516171819
    20212223242526
    27282930  
  • Archives

Authoring for the Cyclorama


The Cyclorama is a cylindrical 360° display. Seven (or fourteen) projectors, driven by Lighttwist, surround the audience with a high definition image or movie – ambiophonic sound included. The following tutorial explains how to output panoramas for the Cyclorama with Hugin. I start with a full spherical panorama, but any Hugin project will do. Make sure the image covers 360° horizontal FoV (field of view) and at least 30° vertical FoV >30°. Images with smaller FoV will leave part of the screen blank.

Start Hugin and load the image(s). Since equirectangular images usually don’t have EXIF data, enter the image type and FoV as in the window below:

01_load_equirect1

Visually check the equirectangular in the Fast Preview window:

02_equirect_fast_previewOn the Stitcher tab, enter the following parameters:

  • Projection: Cylindrical
  • Field of View: horizontal 360°, vertical 38.5°
  • Panorama Canvas Size: width 7200, height: 800
  • Crop: 0,0,7200,600

03_stitcher_tab1The resolution of the Cyclorama is currently 7200 x 600 pixel, equivalent to 360°x29.3° in a cylindrical projection centered around the horizon. However we do not center around the horizon: the screen will be slightly higher to avoid shadows from the audience inside the Cyclorama. Set the horizon at 1/3 (or 200 pixels) from the bottom (although the human eye is very forgiving). To do so we output slightly more vertical FoV and crop it. Test the result in the Fast Preview window:

04_cyl_fast_previewThe white line is the crop line. When you’re happy with the result, stitch!

060608cesarea03a_cyclo

Exhibition

As a last step, log on to Ultra Wide Views, select the Cyclorama 2009 exhibition on the upload form and beam the result over. Thank you! It may be shown on the Cyclorama during LGM. The exhibition’s theme will be Horizons. The panorama used for this tutorial is the Mediterranean Sea seen from the coast of Israel in Cesarea. On the beach are the remnants of a two thousands years old Roman aqueduct.

Important Notes:

  1. Make sure your input image has enough resolution for an output at 7200 pixels horizontally. Full spherical panoramas in the range above 6000 pixels are OK.
  2. Hugin does not apply interpolation filters (yet). Ideally you either first resize the panorama to 7200 horizontal pixels and then run it through the above process, or you output at recommended resolution and resize it later. To do so, set the appropriate FoV values, then click on Calculate Optimal Size. Stitch. Open the result in your preferred image editor, resize and crop. Double-check that the resulting cropped image is 7200×600. Warning: some image editors do not resize well the 360° seam.
  3. Not all content is appropriate for cylindrical projections. The crop lines at +20°/-10° vertically often cut away important detail. Choose a panorama that fits the medium.

2 Responses

  1. Thanks for the tutorial, it’s very easy to follow (and I discovered how awesome the fast preview window is).

    When will the selected images be announced?

  2. @Daniel: Happy you like the tutorial and the fast preview.

    The exhibition is due to start May 6 and technically a slide can be added or removed easily up until the start.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s