Overlay animation effects?

[AERenoir]

So in the Magical Diary game when you do magic spells they seem to be glowing like they're on Overlay or Add layer effect in Photoshop.
(see in the trailer below)
http://www.youtube.com/watch?v=YZ1Kwu0kGMc

Can Ren'py put images on "layer effects" like that?

[Asceai]

Yes.

But that's the only one.

EDIT: By the way, Magical Diary is Ren'Py so anything in Magical Diary can be done in Ren'Py =P

[AERenoir]

Oh, yay! How do I write in that additive effect to the code? :O

(I wonder if the "change eye colour through gradient bar" thing that MD has is a trade secret because that looks really neat)

[Asceai]

Oh, yay! How do I write in that additive effect to the code? :O

Using ATL. Same as alpha transparency, but the keyword is 'additive' instead of 'alpha'. If you don't know ATL I wouldn't be adding expensive magical effects to your game juust yet.

(I wonder if the "change eye colour through gradient bar" thing that MD has is a trade secret because that looks really neat)

I don't know exactly how Magical Diary does it, but AlphaBlend, Solid and LiveComposite are a good combo for that. It wasn't necessarily done that way though.

EDIT: Here's something I wrote on the subject. (there's also example code further down) It's hair, not eyes, but it's still a method of allowing an arbitrary colour for a body part to be specified. Just a matter of adding the colour selector.

[AERenoir]

Oh, I know how to do ATL. I just don't know where the additive keyword should be placed into.

[Asceai]

Just throw in 'additive 1.0' somewhere, like you might put in 'alpha 0.5' to get a 50% transparent image.

[Spiky Caterpillar]

Oh, yay! How do I write in that additive effect to the code? :O

(I wonder if the "change eye colour through gradient bar" thing that MD has is a trade secret because that looks really neat)

Not a trade secret; I just fed a ui.bar's output into im.MatrixColor()'s im.matrix.hue(). Something like im.MatrixColor('faces/eyes-big.png',im.matrix.hue(value_from_bar)) should work.

The additive/subtractive/dodge effects in Magical Diary/DW/SG are actually rather messy hacks, as they predate official support for blend modes. (For that matter, I'm not sure if mainline Ren'Py supports blend effects in the software renderer at all or only in the accelerated renderer.)

[Asceai]

Not a trade secret; I just fed a ui.bar's output into im.MatrixColor()'s im.matrix.hue(). Something like im.MatrixColor('faces/eyes-big.png',im.matrix.hue(value_from_bar)) should work.

Huh. I think I need to learn more; I was under the impression image manipulators had to all be set up during init, but I guess not!

[AERenoir]

Oh, yay! How do I write in that additive effect to the code? :O

(I wonder if the "change eye colour through gradient bar" thing that MD has is a trade secret because that looks really neat)

Not a trade secret; I just fed a ui.bar's output into im.MatrixColor()'s im.matrix.hue(). Something like im.MatrixColor('faces/eyes-big.png',im.matrix.hue(value_from_bar)) should work.

Oooh, okay. Now I have to study up ui.bar functions, then...