Projecting on domed surfaces



  • Hello friends,

    Does anyone have any experience of projecting on domed surfaces (the concave side) with izzy? I have a project coming up and I'm feeling a bit out of my depth on this one.
    is the 3d mesh actor used? Can you pre - render the video in some way to cut down computer processing? Has anyone used any particularly good hardware to achieve good results.
    the dome will be close to the audience so a sharp image is what I'm after without the picture sliding away at a peculiar angle.
    thanks


  • i directed my first short fulldome film earlier this year. i'll fill you in with as much as i know about the technical set-up, but i've asked the dome crew for the vital bit of information that i don't have, but would be useful for you - when they send it, i'll update you.

    this is for 360 degree dome.
    so: the film was edited on a square canvas with a circular mask. this was then exported, frame by frame as jpegs. each jpeg was fed through photoshop, and spherized into a 4:1 rectangular canvas, then recombined into a movie. (apparently there's a fulldome plugin for after effects which will bypass this process and do the conversion in one go)
    then the movie is played from a pc into a matrox triple head to go, and fed to 3 projectors.
    the clever bit is where the 3 screens are tweaked and blended to fit the dome. the guys use a bit of software (originally designed for flight simulators) to calibrate the 3 screens and get the image to fit the space. its a lot of tweaking points on a grid to match up on the internal surface of the dome. i'll let you know the name of this software when i get the info. it takes a feed from an external monitor out, so it should work fine with the right size stage output from isadora, although this crew were using a different vj software for playback.
    and that is pretty much it in a nutshell. a big, complicated, time-consuming nutshell. hope its useful...


  • Hi wassarts,

    Back in 2004 I created Wetland, an interactive sound and video project in which the video images were projected onto curved surfaces. The videos were created as usual but distorted 'in-projector' using the 3dReform function/software that NEC developed for their more industrial strength projectors (from memory I was using a couple of their MT1065 model). 
    If I remember correctly, one of the easier default settings in the application was for projecting onto a sphere. 
    My project was a bit fiddly to set-up but the 3dReform meant the video was very neatly pinned to the curved surfaces and appeared undistorted.
    You can see/read some archive video, images and background on the project at [www.headofideas.com.au/wetland/gallery.html](http://www.headofideas.com.au/wetland/gallery.html)


  • ....the distortion/blending was done with nthusim

    http://www.nthusim.com/


  • if you have to use isadora, then you'd probably need to use the 3d mesh. I have not used it so I can't talk about the performance.

    Pre-rendering is a good option but only for preparing content. There is a dome plug-in for aftereffects, not cheap, that i've used it and it has a few parameters you can't do with spherize or warp effect. [here is an old clip of mine](http://www.myspace.com/video/vid/9575252#pm_cmp=vid_OEV_P_P) (it did not work as there is more to it than just aligning the image to the distortion map.) Once you have your content dome-fied then you'd have a bit of work to set-up projector masking and edge-blending. 
    The Mapio free-frameGL plug-in has an option to warp images in addition to frame blending etc, but it may not be the proper tool. It's great as it's a live effect.
    Isadora can't use it yet, but if you use it with something else you don't have to create a full continuous projection, but rather something like this:
    [http://www.youtube.com/watch?v=cY6UOPp-adQ&feature=youtube_gdata_player](http://www.youtube.com/watch?v=cY6UOPp-adQ&feature=youtube_gdata_player)


  • These are all very useful comments and I thanks you very much for the considered responses, partly based on your comments I have managed to persuade the gallery to take an alternative route as they dont have the dome built and I only have one week to produce the work for it.

    I think we'll go for a curved surface made from 8 flats, I'll map the projection through syphon into mad-mapper or if I have time map it straight from Izzy.
    As artists we must make some firm decisions based on fact and what is achievable in given time frames.
    thanks again
    bob

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