I am creating a GIF animation over a static background. I want the background to have a drop shadow. For some reason when I do this, my drop shadow turns solid... it does not fade out. It is just a solid offset layer. I can't for the life of me understand why.

Any ideas?

It sounds like you are using the Gimp 2.8 drop shadow filter. Is that correct? For that to work the image is in RGB mode.

Indexed color mode as used by gif only has transparency either on or off. Going from RGB to Indexed results in losing the drop shadow semi-transparent pixels. see screenshot 1

First thing to do in RGB mode is merge the background and drop shadow layers.

Still in RGB mode you then have a choice.

Either, lose the transparency of that bottom layer as screenshot 2 Layer -> Transparency -> Remove alpha channel Then export as an animated gif. see screenshot 2

Or, before exporting as an animated gif, convert to Indexed Mode. Image -> Mode -> Indexed and Enable dithering of Transparency. That gives the impression of shading. see: screenshot 3

rich: www.gimp-forum.net

On 06/12/2018 09:41 AM, ustharp wrote:

I am creating a GIF animation over a static background. I want the background to have a drop shadow. For some reason when I do this, my drop shadow turns solid... it does not fade out. It is just a solid offset layer. I can't for the life of me understand why.

Any ideas?

Unfortunately the GIF format does not support partial transparency (no alpha channel). If you know the exact background the GIF will be displayed on, you can use that background as an opaque layer - with a soft-edged drop shadow added where you want it.

:o)

I would suggest trying an animated PNG file, which supports partial transparency (alpha channel present) but alas, if your animation will be displayed on a web page, Inernet Explorer and MS Edge do not support that format (according to Wikipedia - may be old info).

I never made an animated PNG file, so any advice on that including whether the GIMP can make them, or whether you would have to make the frames in the GIMP and assemble them with another program.

:o/

I have an idea for you, but I have no idea whether or not you want to spend this kind of time greating an animated GIF. GiMP can of course do it, but you would almost be better off drawing the cells by hand and usinging your smart phone and a GIF-making app to get the final result.

If you care creating a drop shadow, you are using layers to get there, right? Even the filter uses layers. But in GiMP, to make an animation, each cell has to be a layer -- so you must effectively flatten the layers every time you make a new cell.

My thought is this: you need to have 3 images open: 1. Your master image in which you are creating each cell (using layers) 2. a "slave" image in which you flatten the master and then convert from RGB to indexed
3. your animation file, in which you paste each new cell as a layer as you convert it

If that workflow doesn't make sense to you, I can give you more steps to follow. The idea is that you are doing the high-res, high-quality work in the master image; you are taking the master image each time you change it and flattening it down and reducing the colors for use in a GIF; and you are assembling the GIF in its own indexed-color file.

Hope that helps!

On Tue, Jun 12, 2018 at 12:37 PM ustharp wrote:

I am creating a GIF animation over a static background. I want the background
to have a drop shadow. For some reason when I do this, my drop shadow turns
solid... it does not fade out. It is just a solid offset layer. I can't for
the life of me understand why.

Any ideas?

-- ustharp (via www.gimpusers.com/forums) _______________________________________________ gimp-user-list mailing list
List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list

See attached for my very rough-and-ready 5-cell animation with a drop shadow.

On Tue, Jun 12, 2018 at 12:37 PM ustharp wrote:

I am creating a GIF animation over a static background. I want the background
to have a drop shadow. For some reason when I do this, my drop shadow turns
solid... it does not fade out. It is just a solid offset layer. I can't for
the life of me understand why.

Any ideas?

-- ustharp (via www.gimpusers.com/forums) _______________________________________________ gimp-user-list mailing list
List address: gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list