Friday, May 31, 2013

using After Effects instead of Blender for post-processing

In an earlier post, I'd mentioned using Blender for rotating fulldome frames. The rendering times for 2K frames with Blender was around 22 seconds per frame. Decided to try out Adobe After Effects instead. Dug out the old AE 4.1 box set which we'd purchased in 1999 or so. AE did the render of the 2K frame rotate faster than 1fps, since it's not doing any ray-tracing and instead just doing 2d transforms. Definitely a timesaver.

Saturday, May 25, 2013

fulldome frame from celestia using the cube2dome method

Inspired by Ryan Wyatt's article about making fisheye frames from partiview using 6 cube faces, and with the help of code from Selden to display the six different fields of view top, down, left, right, front and back, hacked out a series of screenshots from Celestia and stitched them together to make a fulldome domemaster fisheye image with the help of the archived version of Paul Bourke's cube2dome_linux. On my first try, the registration was not perfect:
Then I thought maybe this was because the frames were not perfectly square. In order to get exactly square pixels, I had to resize the Celestia window to get exactly equal width and height. The getscreendimension function gives the x and y, but there is no "setscreendimension". So I just used the example script at for getscreendimension and kept calling it after tweaking the window size till I got 1002 x 1002 - it could have been any square size, I suppose. Taking those screenshots and making a domemaster, this time it meshed perfectly:

But this is just one frame! So I have to decide whether to pursue this time-consuming route or just purchase the Software Bisque Theater edition as suggested as one of the alternatives to Uniview by Paul Bourke.

Wednesday, May 22, 2013

exporting clips from Celestia

Tried exporting video clips from Celestia. Running it on secondary display at 1920x1080, tried exporting at 1280x720 with Xvid codec and as uncompressed avi. The Xvid codec version seemed to be better, more quality rendering, at around 11 fps. The look on the dome of course would be the final test. The idea is to warp the exported video after cropping it to a square shape and see if lower third centre view would be good for globes and such.

Tuesday, May 14, 2013

list of astronomy software

This page has a useful list of Astronomy and Planetarium related software:

offline rendering of fulldome fisheye frames using partiview

Ryan Wyatt has documented how he rendered fulldome content using partiview and Paul Bourke's tga2dome -

Seems a bit process intensive. First rendering 6 TGA cubes per angular fisheye frame, then creating the fisheye, and then in our case, warping the fisheye. Probably easier for me to use pre-rendered content as of now. Would be interesting to do a study of whether this process takes more or less time than the Blender render method which was around 1-2 minutes per frame.

There are other partiview resources listed at

Celestia seems to be able to render multi-view images as given in this old forum post but is limited by the resolution of the output screen.

Friday, May 10, 2013

planetarium systems review

Over the last two days, I could see two different planetariums. Interacted with the staff, saw their features, equipment. Different feature sets, different costs.

Bangalore Planetarium - single projector mirrordome system. Mitsubishi UD8400 projector gives 6500 lumens. Unidirectional seating is achieved through leaving two-thirds of the 15 m theatre empty, seating only 120 instead of 200. They have fulldome shows as well as traditional shows using the star projector, but demand is more for the former. They are making new shows with the help of an animation studio in 3DS Max.

Their website is

Calicut Planetarium - Upgraded just last week to Carl Zeiss Powerdome fulldome setup, with all the bells and whistles including a hybrid opto-mechanical system which is supposed to come in a few months. They use 9 JVC DLA-RS65 projectors with the Powerdome system featuring Uniview which can render astronomical objects in realtime, and also save sequences, and allows for show creation by dragging and dropping sequences into a timeline. They drive their HDMI ports over fiber, with the control systems in a rack in another room. They have converted their seating to unidirectional, and are able to seat 200 in their 15 m dome.

Their website is

Subjective review: I saw Dawn of the Space Age at Bangalore, and Realm of Light at Calicut. In both cases I was near the rear of the theatre. In both cases, I felt the brightness was quite adequate, though in Calicut I thought some of the dark parts were too dark - like the whale swimming part. Maybe some gamma issue. Could not make out any great improvement in clarity over the single projector setup at Bangalore, except for the area behind the audience - when we use a mirror-dome setup, the area immediately around the mirror is somewhat washed-out, distorted. When observed close to the screen, the pixelation is evident at Bangalore, as it is at our planetarium, but for most of the audience, it is not visible. This pixelation is not seen in the 9 projector setup. I could make out some boundary artifacts of the 9-projector stitch boundaries during the fade-to-black parts. The overall sharpness was probably limited by the 4k dome master, or maybe by all the realtime slicing done to send 9 separate video feeds. Our Space Opera show is quite comparable in terms of audience wow-factor :)

From the audience point of view, the 100x times more costly setup does not deliver that much extra bang for the buck. But from the planetarium executive's point of view, compelling show creation tools are a great asset. Being able to create detailed flythroughs in realtime is a great boon. But patience is a virtue, and if uniview can be licensed and used to export offline for a reasonable cost, we can get most of the advantages of that setup, too. Something like a front-end for the process intensive method of rendering using partiview described here.