Is there a code for a moving light source?

[MegaSobi]

Like, say I wanted to use a sort of napalmish/Magnetic Shockwave-esque geyser effect in the background, but I wanted the stage itself to alternate between illuminating and darkening to reflect that. Is there a code for that (maybe some bgctrl thing), or would I just have to do that by hand in Photoshop or whatever?

[Odb718]

I'd image if you made a type of transparency in an animation that only played at the right time it'd look very similar to what you want.
You could just use a regular gradient type image with transparency. Then what ever sprites below it would be dyed to the new color. So you could add a yellow see-thru effect and it'd look like it was being lit up. Blue/Yellow/what ever color the Magnetic Shockwave is would look the best.
It might not look as good as doing all of the lighting yourself, but it'd be a lot easier.
If you wanted the light source to have the map cast shadows, this method isn't the best idea.

[MegaSobi]

Out of curiosity, why wouldn't it work well for casting shadows?

A moving gradient does sound like a good idea. Would there be any way to alter the brightness of it in the .def file or would I have to do that in Photoshop?

[Odb718]

Well you'd be able to alter the transparency inside the def. It'd look like the light was getting dimmer.
In my head the gradient would be either circular or a flat plane. What ever you put it over would have a pretty uniform look to it. Besides the gradient's tapering off.
But say, there's a light post that's the light source. Then on a layer in front of it is a car and a mail box. The side of the mail box and car facing the viewer/player wouldn't be getting light on it. The side to the light would. So it'd be in a shadow. But if you just overlaid the gradient, the entire car and mailbox would be lit up. So there'd be no shadow.
If the car and mail box were behind the light, then it'd work fine.

[MegaSobi]

How would you make the gradient affect the players? I didn't think background elements could do that.

[Odb718]

You just set it as a foreground layer and it'll be in front. It will go away with assertspecials, but return once that's done.