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david van brink // Wed 2015.03.4 17:03 // {dome}

Note on om_sphere2dome

As introduced in yesterday’s post, you can download my Mac command line tools, om_sphere2dome to help convert Modo spherical projection images to fulldome domemaster images.

For reference, I’ll here post the tool’s help info, so you can see its feature set more easily.

poly@omino-8999 domework: om_sphere2dome --help

om_sphere2dome

This command line tool transforms a spherically-projected
image file to a Domemaster image file (180 degree fisheye).
The source image is a 2:1 aspect ratio equirectangular
projection, as produced by Modo's spherical camera. The
center square is extracted and transformed.

See http://omino.com/pixelblog/2015/03/03/modo-for-fulldome-
part-2/

--help
Optional. Show help.

--infile=<file name>
Required. A source .png or .jpg image, 2:1 aspect ratio,
spherically projected.

--outfile=<file name>
Required. The output .png or .jpg image to write, square,
Domemaster projection.

--vflip=<yes or no>
Optional. Vertically flip the image.

--size=<number>
Optional. Size of output image.

--azimuth=<number>
Optional. Shifts view negative-left or positive-right
in degrees.

Written by david.van.brink@gmail.com, 2015. Uses Lode Vandevenne's
excellent lodepng library from http://lodev.org/lodepng/. Uses Rich
Geldreich's wonderful single-file jpeg library from https://code.google.com/
p/jpeg-compressor/. 8x8 font created by John Hall, http://overcode.yak.net/
12, no longer with us.
oh, i dont know. what do you think?


david van brink // Tue 2015.03.3 19:26 // {dome}

Modo for Fulldome, Part 2.

This post will describe a means of creating fulldome domemaster images using Modo.

What is a Domemaster?

The interchange format for digital planetarium movies is a Domemaster (or Dome Master). Since planetaria require extremely high resolution (4k at least, some are using 8k), these are often delivered as a hard disk full of individual, numbered PNG files.

The format of each image is a disk, where the center of the image is projected to the top of the planetarium dome. Here’s a calibration image I found somewhere…

DomeCalibration1k
This is an “equal-azimuthal projection”; radius from the center corresponds directly to latitude. A nice attribute of this projection is that it looks quite natural even when it is flat. In this image, the audience would be facing South.

What Modo Provides

Modo’s camera has several projection modes, including “Spherical”. This renders a full sphere of imagery from a single camera point. It draws this into a projection known as “equirectangular”. You have probably seen a world map like this:

EquirectangularWorld

I grew up with one in the hallway. It fascinated me how Antarctica was smeared across the entire bottom edge. In this projection, latitude goes vertically from -90° South to +90° North, and longitude goes horizontally from -180° East to +180° West. To make the gridlines square, the width is generally twice the height.

I did some experiments with Modo’s spherical camera. The model is a closed sphere, with the axes labeled. Modo’s standard axes are Y-up, X-right, and Z-towards-you.

DomeModoModel

And here is Modo’s rendering, using Modo’s Spherical Projection Mode.

DomeCamera90Up

Things to notice:

  1. The center of the render is from exactly behind the camera.
  2. We only need the center square for our dome master (half the spherical scene).
  3. The image is inverted (the “y” is backwards).

To address the first two, in Modo we point the camera exactly away from our center of interest, and we use the Frame Properties’ Render Region, to skip rendering parts of the scene we won’t need. The saved files will still be twice as wide needed, though.

DomeModoModelCamDown

And here is what what gets rendered!

DomeCamera90Down

Making the Domemaster

That’s better, but still inverted, and not a dome master. I wrote a command-line tool, which reads in a JPG or PNG spherical-projection file as Modo produces, and writes out a domemaster JPG or PNG file. You use it like so, from a terminal session:

poly@omino-8999 domework: om_sphere2dome --infile=sphereImage1.jpg --outfile=dome.jpg
infile: sphereImage1.jpg (1024 x 512)
outfile: dome.jpg (512 x 512)
writing dome.jpg...
write result: ok
poly@omino-8999 domework:

Running it on the last render, we get (“ta da!”):

DomeCamera90DownDomemaster

This is a correctly formatted domemaster image. (Excepting that it’s only 512 pixels across, which will be singularly disappointing on a 75 foot dome screen. But you get the idea.)

As of today, the tool is in primitive form, and has limited image quality, and only for Mac OS X at the moment. But if you come across this and need it for Linux or Windows or have a feature request, or want the source code, please email me, poly@omino.com. It’s a living work. As it is, it’s just barely sufficient for my needs, and no more.

Also, just to reiterate, this is a command line tool; you’ll need to be comfortable with shell scripting to make full use of it. You might even need to chmod it after downloading. If that hasn’t warned you away…

Download om_sphere2Dome.

For Photoshop — Andrew Hazelden maintains this set of installable actions which can also do this transformation. For converting a whole Modo movie render, you’ll need to do a bit more scripting on top of it, and it will run fairly slowly… but it’s great to have options! His action set has many other tools as well.

oh, i dont know. what do you think?


david van brink // Tue 2015.03.3 17:17 // {dome}

Modo for Fulldome, Part 1.

I’ve recently been trying to use Modo to render images compatible with digital planetariums. If you want to know just about that, skip straight to Part 2.

Meanwhile, here in Part 1, I’ll give a quick introduction to planetarium video.

Hayden

PlanetariumProjector

I remember visiting the Hayden Planetarium many times as a child, growing up in Manhattan. In the center was a queerly articulated two-headed beast. This was the sky projector, with lovingly-crafted high precision star maps to project glorious pinpoints of light onto the hemispherical theatre ceiling. Shows would be augmented with maybe a slide projector or two, or even a movie projector. The operator had a microphone, a flashlight with an arrow-shaped cutout, and not much else. Those were the days.

Now they’re all digital. Since I love digital video, this is pretty cool.

I recently had a very educational visit to the control booth of Chabot’s “Ask Jeeves Planetarium”, and their resident astronomer/projectionist Ben Burress brought me up to speed on how these newfangled contraptions work. Here’s what I learned; some of this is idiosyncratic to Chabot’s particular installation.

Harware.

  • A dome is typically lit by 5 to 7 projectors, spaced around the edges and one for the top. Chabot uses 6.
  • The theatre is typically driven by multiple computers in their server room, one for each projector and one for audio
  • 5.1 audio.

DomeVideoGridFromWikipedia

Software.

  • There are various softwares available for live shows. Chabot uses “Digital Sky 2.” This astronomy software uses a database of our galaxy and solar system, letting you fly around. The planets are wrapped in NASA textures, light from the sun is computed dynamically, you can move in time and space. They can also import assets (like the International Space Station, for example) to add to a particular show.
  • Playback of “tiled/encoded” pre rendered content. Recorded playback consists of a movie for each projector, played back with perfect frame synchronization.
  • There is a small but growing body of other softwares, including VJ tools and the like, for domes, too.

Content.

Chabot supports several kinds of content, both live and recorded (not sure how similar other theaters would be).

  • Live Digital Sky 2 shows. A combination of preprogrammed cue points and assets (specific camera positions in time and space), and live control, to perform a typically 10-40 minute presentation. Takes two people to perform, usually, one to operate the dome & software, and one to narrate.
  • Automated Digital Sky 2 shows. An automated recording of the control operations and narrations from a live show. Files are compact, as it only has control messages.
  • Recorded Digital Sky 2 shows. Like an automated show, but it has been rendered out to video files. These files are huge. Ben said they do this a) to share a show with another theatre (who may not use Digital Sky 2), and b) they found that certain huge high-polygon assets, like a topographical Earth model, sometimes crashed when performed live.
  • Automated laser music shows (like Pink Floyd). They have additionally a laser projector (not Laserium™, some other maker) which can play back recorded, synchronized control sequences
  • Recorded movie files. This is my main interest, some details of which will be covered in Part 2.

Content Creation.

The Ecosystem of dome video involves several pieces.

  • A Dome Geometry File. This is a calibration file for a specific theatre describing the geometry, color balance, and brightness for the several video projectors (generally from 5 to 7) which span the dome surface.
  • Dome Master content movies. A content creator generates a Dome Master which looks like a square movie with content within a central disk. The disk maps elevation-angle to radial distance. These are often shipped on a hard drive, with numbered 4096×4096 PNG files, like MyPlanetariumShow_12345.png. Audio is typically a Dolby 5.1 AC3 file.
  • Nonrealtime processing. The geometry file is used to “tile” the Dome Master to separate movie files (MPEG? not sure), which are ready for playback on each projector.
  • Realtime Digital Sky 2. Their astronomical software can run on all the projection computers simultaneously, and do live tiling based on the geometry files.
  • Not available at Chabot: Realtime Dome Master tiling. Some theaters are equipped to take HDMI 2k or 4k input, and do live tiling based on the geometry file. This is used by VJ’s. Chabot doesn’t have this, currently.
oh, i dont know. what do you think?


david van brink // Sun 2014.04.13 15:24 // {after effects}

Omino Plugins 2.1 for After Effects

(After some back and forth regarding broken DLLs on our release two weeks back…)

OminoSuite21

By popular demand, the Omino Suite including Kaleidoscope and Snake is now available for both Mac OS X and Windows.

Notes for release 2.1 are:

  • Available for Windows and Mac OS X
  • Works on AE CS6 and Later
  • Installed manually by dragging
  • Kaleidoscope speedup with multithreads
  • Snake rendering errors with tiny holes substantially reduced
  • Minor parameter name changes (old projects still work fine)

Get it at the first link on the download page.

How To Install

In the zip file are two folders, one for Mac OS X, and one for Windows. Drag the appropriate folder as shown below.

OminoSuiteMacInstall1

OminoSuiteWinInstall1

Any problems (or feature requests, of course) please comment or email me, poly@omino.com. Enjoy!

6 comments
sandra // Thu 2014.05.29 07:087:08 am

Hi, I hope you can answer me as quick as possible, because I am having a problem with your Omino Snake plugin in combination with After Effects CC. When I am following the tutorial on vimeo about the layer and path thing, it’s not connecting to the image I am using. I also tried to put the image in a new composition, but that doesnt help. I hope you can help me out because I really like the plugin!

david van brink // Thu 2014.05.29 13:121:12 pm

Hello —
The most likely two things are:
1) there’s a Bug where the snake image size start as 1%, so too small to see, set slider up to 100%.
2) the vertical-offset needs to be set to around 1/2 the height of your snake image.

That might be the issue, best.

sandra // Thu 2014.05.29 22:5610:56 pm

thanks for your quick help. I am a bit further now, it is showing two circles now instead of nothing. here is a screenshot of what i see now http://oi57.tinypic.com/2psocnk.jpg. I am not able to see my puppet anymore when i click the path-layer off. I am still doing something wrong but i am following this tutorial https://vimeo.com/66024290 step by step…

sandra // Thu 2014.05.29 23:0511:05 pm

Sorry for al these reply-bombing. I am further by setting the scale to 80%, but it is using my image the wrong way. the left puppet is how i want it to show on the path (like your snake) but it is turning it into the one you see on the path.. what am i doing wrong? http://oi58.tinypic.com/dbo9iv.jpg

david van brink // Thu 2014.05.29 23:2611:26 pm

Ah, yes, the “snake” image has to be horizontal, long in X and narrow in Y.

sandra // Thu 2014.05.29 23:4111:41 pm

Wow thanks for your quick reply! that worked! now another problem (hope its the last one!) when i want to set the keyframe for it to move, it is only visible in the first frame, changes color in the second en then disapears.. so i cannot set the ‘advance’ to when i want it to ‘snake’

oh, i dont know. what do you think?



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