When in Dome…

The Morehead Planetarium & Science Center Production Blog

Archive for November, 2011

For a long time I was a 3ds max user, and only in the last year have I switched to Maya. One tool that 3ds max had that was incredibly useful for building hard surface or objects that repeat themselves was the array function. Thankfully, I found a script developed by Ed Caspersen that brings this functionality into Maya.

http://www.creativecrash.com/maya/downloads/scripts-plugins/utility-external/copying/c/array-for-maya

I used this tool to produce the following model of a launch tower in less than 2 hours.

With this you can build a small section of geometric detail and control how it is replicated in any direction, and even set it to get gradually smaller. Working in a 4k immersive format, you can only get so close to textures before you start to see the individual pixels or see the resolution soften. Having the extra geometry helps break up the visual landscape and make up for those instances where textures start to fall apart. It’s perfect for building repeating shapes quickly and adding the much needed detail that the fulldome format demands.

 

One of the dangers we run into during our productions has been object distortion. It’s most frequently seen when you fly towards or away from a moon or planet. That dreaded bulge is caused by the closest part of the sphere being much closer and therefore much larger than the farther parts of the surface. We have been actively trying to avoid these situations in our shows, as it tends to break the illusion of immersion. Sometimes, however, it is unavoidable, either through demand of the script or storyboards. It is in these cases that we try to make these close-to-camera actions happen as quickly as possible so as not let the mind start to think, “Boy, that really looks strange!”

Here’s an example I quickly threw together showing various distances.

Designing models and assets to be used in Fulldome video requires you to think about a combination of variables.

  1. How long will it be on screen?
  2. How fast is it moving?
  3. How close will it be to the camera?
  4. How many times will we use it?

We developed this method of evaluation after our first production, during which we learned the importance of pre-visualizing our 3d scenes before even building our models.  The following is a lunar vehicle we designed and built custom for a sequence on the Moon. In the final shot, the vehicle was seen from a long distance aerial flyover and was on screen for a short time.

 

With the time and resources put into this model, we will re-purpose it for another show, should the need arise.