That works for me, It does give the illusion of motion/rotation :-)

So lets say one image was blue/green clockwise spiral, and another was a primarily yellow counterclockwise spiral.  Rotate them both opposite directions, and you'll get apparent motion towards the center where there is none.  Of course the effect must be measured as where they don't overlap you will see the naked colors.  As for sequencing the startup to make the portal grow, I was just thinking fire up the image most biased towards being brighter in the center, then the next brightest farther out.. then the outer rim.  Should be good enough.  

I can strobe them, play with brightness, change rotation speed/direction... later.  The plan for the most bang for the buck was just on, with the servo doing constant rotation.   So you got the rotation of the portal built in, but instead of just simple images or image parts... using the overlapping of the design of the images themselves to generate the false motion to or away from the center.  Get it?

Looks fun !

I don't care about the expansion/contraction really, although firing up the blue/green center first may work for that.  What I really wanted is you to simulate overlaying the colors so the constituent parts of the image move independently, and biasing the addition of the spirals to generate false motion towards the center when they are rotated over each other.  Two will rotate the same direction at slightly different rates, and the other with rotate the other direction.  Like those animated waterfall pictures.  They have a static image, and by varying the brightness via a looped shadowmask behind it, they generate false motion.  Like this:  https://www.youtube.com/watch?v=l00rbJqdniQ

Ok Daren, I've been working on this problem all night, I checked out the youtube vid and that's cool, I tried it in photoshop and I'll show you an example of the effect on the portal but I'm getting now the exact concept of what U want.

To be frank, using a 3 lens projection setup isn't going to work in projecting an image as if we were opening a star gate. U R bound by 3 static disks, with static images.

1) We can use a very old method called a " Phenakistiscope,"  it was the first widespread animation device that created a fluid illusion of motion. The phenakistiscope is regarded as one of the first forms of moving media entertainment that paved the way for the future motion picture and film industry. It is sometimes compared to GIF animation since both show a short continuous loop. 

Here is a link so U know what I'm talking about; 

http://en.wikipedia.org/wiki/Phenakistiscope

I'll PM U a sample GIF I made using the "waterfall" method used for animating a static image.

If U think about how those "star shower" projectors work like @ xmas time, they use static images on what they call "slides", they just rotate around looking pretty, what U want is something very complicated believe it or not, not impossible but complicated.

U want the illusion of an actual portal opening from start to finish in a loop type fashion, it can be done but with a lot more than just a few spinning disks and lenses, I believe the best course of action is what I have mentioned previously about the Phenakistiscope type disk.

I also understand the idea of the "waterfall" concept as far as those novelty items where they are backlit with a rotating disk imprinted with an alternate image to give the effect of motion.

I'll keep working the problem... :)

I'm not looking for perfection on the first try here.  I also didn't think it would be easy, hence the reason I'm trying to pass the buck on this part to someone with more graphics experience.  :) 

I don't need the portals opening from start to finish.  I wasn't intending to have them 'open' at all for what I was going to do myself beyond the sequential lighting of the images biased towards the one with more stuff in the middle.  I *was* intending to try the waterfall idea with randomized spirals though and since we can control the direction and speed of the apparent motion by reversing the servo, it may produce an acceptable effect by itself.  My mental picture of this has one disc primarily blue/green and more lit in the center, with clockwise spiral arms.  The second disc would have yellow/white counterclockwise spiral arms.  So where they add we get green, and where they are merging and separating due to the rotation of the spirals, we get the false motion.  The effect will probably be too strong if we had full brightness over black, so I'm envisioning the arms as just lighter areas of the original image but we can experiment with this.  The third disc adds in some changing detail as it isn't coupled tightly to the first two due to the difference in gear ratio.

I just thought it was something we could try to incorporate that would make our static images become more than the sum of the parts.  

Thank you for working on this.  

I'm designing it so the image rings/discs can be swapped out as easily as changing the batteries, so I'm sure some experimentation will be happening.