I've created a simple animation where I have four images (bits of steam) that fade in then out in sequence (shown below). This works fine until I export the animation out and convert it to a gif.
As you can see from the gif below, the fade in/out motion then stops working and just shows a hard cut of the images which doesn't look at good. Hopefully someone can help!
Let us try to build an answer out of my comments.
GIF has no real transparency, either a pixel is there or it is fully transparent. That is it has 1 bit transparency. This means you can not fade parts of a image into transparent. There is really no good workaround and there is no real alternative for GIF animations in this case.
If you must, it is possible to build a raster effect where alternate pixels dissapear from view. A bit like dither but on the alpha channel. It is far from ideal, but might better than nothing (altough no animation may be better).
If you want a fading out transition you're going to have to copy the triangles in place with photoshop and lower the transparency each step so its color stays but as that color gets lighter it appears to fade away.
