GIMP#23 Shadow and Shadow Play (Gimp 2.8)
This demo has two parts. The first is a minute and a half demonstrate how to easily add a shadow for a cutout figure added to a scene. It is very flexible. The second part is a demonstration of how to make an animated shadow that seems to move on its own while the figure stays still. Gimp 2.8 is used for both parts.
The basic approach for making a shadow is to start with the cutout on a separate layer, then copy that layer and move it under (behind) the figure. Rendering the copy as difference clouds and then darkening it makes for an effective shadow which you will blend in with Grain Merge. The copy, now a shadow, can be moved independently of the figure to allow the light casting the shadow to come from different directions. The opacity of the shadow can be used to get the right level of dark for your purposes.
The animated shadow is somewhat more complex. It is easiest if you have a second (or more) shot of the original cutout figure to use as a target shadow. This could be the person raising a knife or something else, or could be the person sitting down. Whatever you want the shadow to do. Once you have that separate cutout, you can make a second shadow. From there, it is only a question of how many intermediate steps you want between the original shadow and the final shadow. You copy either the original shadow or the final, and shift and edit it to make it closer to the other so that you get a series of steps moving from one shadow to the next. I find the most effective is to make copies of the intermediate steps to reverse the process, so that when the shadow repeats, it is back where it started smoothly.
Finally, you make a series of layers by copying the background layer as many times as there are shadows and merging one shadow with each background. Then, you make copies of the cutout figure layer for each, and merge those as well. You should end up with a series of layers that are all the same except for the intermediate changes to the shadow. You can the use Animation - Optimize for GIF to make it into animated. Slow down the steps however you like to make the animation look like you want, then save as GIF, making sure to check the box saying it will be animated.
Transcript (and text of closed captions):
The is Ben Langhinrichs with a mini-lesson called Shadows and Shadow Play with Gimp 2.8. In this, I'm going to show you how to take a cut-out figure and put it in a scene, copy and paste it into here, and we're going to create a shadow. The way we're going to do that is we're going to position her where we want her. Label the layers, but now we're going to copy the figure, that layer, then we will isolate it, show just the shadow.
Now, we're going to do Render - Clouds - Difference Clouds, and what that's going to do is give a kind of black and white view, but something with some complexity. It makes the shadow look better. I'm going to darken it, so it's mostly like a shadow. It's in the same position she is, so first we're going to move it a little bit, so the shadow is a little behind her. We can move it around depending on where we want the angle of the light to come from. Play with the shadow itself after we get it in the right position.
Now that we're happy with where it is, we're going to change the mode to Grain Merge so you can see it behind. It's still a little too dark, so we can just change the opacity so that you can see the shadow as dark as you want it to be. And that's how you make a shadow. It's that simple.
But now what if we want to play with the shadow? Taking another of the same figure, but in a different position. I'm going to paste that image, that shadow, in. What I'm going to do is make an animated GIF with a few different transitions from the one shadow to the other, so that it looks like the shadow is leaning back and stretching while the person doesn't move. Kind of a cinemagraph. Put her at a little bit of an angle and a little bit further away so that it looks like there's movement. Play with it a little bit more. Get it where we want it.
Then what we're going to need to do is we're going to need to make several transitions between the different shadows so that it looks like there's an animation almost. What we'll do is we'll copy the figures, the individual ones, and we'll start manipulating each individual shadow. So, there are the two. We're going to start with the first shadow and make a copy of it and change that, and then we can work from that shadow or we can work back from the other shadow. I'm going to do a little bit of both. And then try to move the shadows so they are a sequence. In this one, I'm actually shifting the arms a little bit.
So, once I've got a series of shadows where I want them to be, I'm going to copy the background (layer) multiple times, and merge down each one of the shadows onto a background. And then I copy the figure and I do the same thing. Basically, merge down the figure on top of each one. So now, you watch and I'm going to merge down. One by one, I'm going to merge down each of the backgrounds. Then I'll go to the figure, make several copies of that, one for each layer, and then I'll shift them down and I'll merge those as well. What that does is give us identical layers except for the shadow. This is what we use in Gimp to make an animated GIF. It's just a series of layers.
So now I can go to Animation - Optimize for GIF since most of the image is exactly the same, I don't need it to show. I just need a little tiny bit of difference between each one, which means it's smaller. You'll notice that each layer now has a hundred milliseconds as the time (delay), so it's a very, very fast shadow which is not what we want. We want something more subtle than that.
So, I'll go and edit the layer attributes for each one, change the first one to be a longer time and each of the others to be about a quarter second so that it's not as fast, but it looks like there's a pause before she starts stretching, and maybe a little bit more like a half a second when she's all the way stretched out. Once we go ahead and do that, we can try the animation again. We'll do the playback, and now you'll see that you watch for a moment and then the shadow stretches out as if she's stretching out.
That's the effect we're going for, so thank you very much for watching, and see our other videos.