Q: could you elaborate on the 'dos and donts of speech bubble placement'?
A: sure. when the camera is very far away, obviously the speech bubble needs to be huge in the scene, in order to be a reasonable size on screen. And it needs to point directly to the characters. but the problem that sometimes happens is, there might be a tree or something closer to the camera than the character, which occupies the screenspace where the speech bubble goes. so if you put the speech bubble in the right place on the screen, it will either be partially obscured by the tree, or, it will disobey the laws of occlusion and be in front of the tree when it shouldn't be. I discovered that, if the camera is totally still, in most cases, you can get away with this. in other words, you can put a speech bubble which appears to point to the character on the 2D screenspace, even if its 3D placement would be impossible. in reality, it's actually a much smaller speech bubble, much closer to the camera, and its position is adjusted so it looks like it points to the character, even though if it were actually next to the character it would be behind the tree. So i've learned that you can usually get away with that when the camera is totally still. But when the camera is slightly moving, this absolutely does not work. There is a shot in the most recent video where the camera is across the street, looking toward the characters through the trees. To put the speech bubble actually next to the characters, it would be entirely obscured by the trees. If i cheat the speech bubble and put it in front of the trees, but smaller, this is a disaster because the camera is drifting slightly, and it becomes glaringly obvious that the bubble is much closer to the camera. So i tried to linearly keyframe the speech bubble to stay positioned next to the character, in 2D screen space. This is an even bigger disaster, and it looks like the scene is broken because the bubble is behaving as if it should be behind the tree, but it actually obscures the tree. Then i tried it with the speech bubble in the same place, but a longer stem reaching mostly back away from the camera toward the character. again, with the drifting camera, as the shape of the speech bubble is revealed, it looks truly bizarre. i ended up having place the bubble far off to the right, outside the trees, and make a very long tail on the 2D plane. which looks a little ridiculous and i didn't really want to do it that way, but i tried absolutely every other way, and it's the only thing that seemed to work. And i've also seen it done in comic books, so it's probably the best way