I'm working on a game where the characters will carry around PDAs (personal digital assistants) and the little devices will occasionally "broadcast" info to each other. I want to create an effect that looks something like one of the above pictures. The concentric circles won't emanate from an antenna, but from the PDA itself. Ideally the lines should be very skinny, and should radiate outward from the center, fading (getting more transparent) as they go. I have tried to do this with an animated sprite I made in photoshop with an alpha channel, but it didn't look too good.

Can anybody give this a try with particles or draw_point3d(()? Thanks!

You could simply use a large circle image and then scale it larger while fading away...

Yeah, that's very similar to what I tried. But as it scales up, the line width gets thicker and thicker, which doesn't create the right effect. It must be fairly easy to draw a circle with points -- I should have paid more attention in geometry class!

maybe you can try an animated sprite? or [i have no idea how to implement but] particles?

or a animated model and a good glow shader or something?

...as above, he already tried that

Next idea would be to just manually draw the lines on the screen...

Meaning with draw_point3d(()? or how?

Use mask to create several layers of the cirlce then rearrange in an animated sprite file to clean, expanding lines.

Use a model and animate it (vertex animation). Of course you need to calculate the angle so it always faces to the camera.

That's an interesting idea. Probably easier than making it work in Direct3D or DirectDraw.

make a model of a circle like mk1 said and add particles interpolating inbetween the vertices (make the model invis) set them to like beam or something