Help with making a "half rainbow flare"

[Icey]

I snapshot'd this pic while I was playing Dissidia:FF and I thought about trying to make one of those little rainbow things but I just can' seem to do it for the life of me.



I have gotten close before but I would like to actually be able to do it almost like it's seen in the games/pic.

[Monsieur OUXX]

I havne't played the game so I'm not sure what I'm actually seeing on the picture (real-time 3D I guess?)

If it's real-time 3D, then I guess the rainbow-thingy is not a "real" light-diffraction effect based on "real" rays calculations (it would be too CPU-consuming).
I mean, the CPU is certainly not calculating something like that in real time:


It can mean only one thing: The rainbow is actually made of 2D sprites.

By looking closely at the picture I can actually distinguish two rainbow-colored ellipses:
- the smaller one in the middle, contained inside the bubble.
- the larger one, slightly more transparent, larger than the bubble.

If you create 2 identical sprites of a rainbow-colored ellipse and make them 32 bit, then draw them with different transparencies, then stretch them to different sizes and rotate them dynamically, you might have something pretty close.

To obtain your basic rainbow-colored ellipse sprite, you could start with this image :

- Make all white parts transparent
- Blur it a lot
- Make only bits of the circle visible (make the other sections transparent)

I guess this would give you a basic effect but I also suspect that in your screenshot the programmers also made the luminosity of the ellipses vary (to give some sort of luminescent effect). If you draw your sprites with Calin Leafshade's plugin, then you can also probably tint them to simulate this luminosity variation effect.

[Ali]

I've used pretty much the technique M. OUXX describes to make custom lens flares for video compositing. However, for the effect to work it needs to an additive or screen multiplier to make the background brighter where the flare appears. I don't know if Calin's plugin allows for that, but with standard AGS transparency the effect will not be as convincing.

[Icey]

I really gotta notify myself of replys, Thanks you guys. I will see what I can do. If I can get it then hey I finally was able to do but if not then I'm fine with the way I do it now.