< https://yingyueue.myblog.arts.ac.uk/2 0 2 2 /1 1 /2 4 /compositing/>?

By Yingyue Feng < https://yingyueue.myblog.arts.ac.uk/author/20028722/?

24th November 2022 < https://yingyueue.myblog.arts.ac.uk/2022/11/24/compositing/>

After the entire animation is rendered, it is time to start compositing. My topic is the cat on the cloud. Next, I need to add some clouds to the scene. According to the principle of lens language, I try to have different movement directions for short stories without moving. For example, when shooting a person walking, you can first shoot him from the left to the right of the camera, and then shoot obliquely in the next shot, so that he walks from the lower left corner to the lower right corner. You can change the direction again next time. In short, it is necessary to have different movement directions as much as possible, so that the whole short film can be more exciting. My lens is a fixed lens for convenience, so the whole animation needs to increase its interest when the lens remains unchanged, that is, its movement route. I plan to use the different moving directions of the cloud combined with the moving direction of the cat to create resolve this matter. Make my short films more exciting. Otherwise, if only the cat in the short film is moving, the whole short film will be too boring.

https://www.youtube.com/embed/FBolPP9VMTY?feature=oembed

To make my animation more interesting, I don’t intend to make all the clouds move in one direction. First analyze the cat’s action path, from the left of the video to the right of the video, then turn to his left, and finally walk to the middle of the entire screen and sit down. And the cloud I’m going to add has three layers. The clouds in the foreground above the video and below the video are moving from left to right. The cloud layer in the background below the video spreads from the middle of the video to the bottom of the video. In this way, the movement path of the clouds below the video will form an L-shape from front to back, and then from left to right. This also happens to form a circle with the cat’s action path. Of course, I also tried to move the clouds with different action paths, but if the moving paths of the clouds at different levels in the video are completely opposite, it will appear very abrupt. But if all the clouds were moving in one direction, the whole video would look very boring. After many attempts, I settled on the current solution. Background clouds on the sky and foreground below, with layers moving from left to right. Clouds in the lower background spread downward from the center of the middle video.

Added another animation after the clouds were all done. Finally, after the cat sat down, a group of birds flew from the lower right corner of the video to the upper left corner of the video. This is a slanting upward movement trajectory that is different from the previous trajectory. It also makes the boring time after the cat sits more interesting.

Next was to color the whole scene, I couldn’t make my work black and white, that would be too bad. After I arranged all the cloud layers, I grabbed the key frame of the last frame directly in After Effects, and chose to export to photoshop format when exporting, so that the work I exported will be divided according to the layering of the previously synthesized video. Many layers. This also makes it easier for me to add color when coloring the video at different levels. Of course, in the final export, not only can the work in photoshop format be directly uploaded to After Effects, but also it can save time for subsequent synthesis and modification and make it clearer.

In order to know what color is more suitable, I found some references on the Internet. It was a sky reference. Excessive, the sky is white clouds, the ground is a city, very beautiful pictures, and the colors are also very beautiful. Although the overall color looks very complicated, in fact, the entire color change is changed according to the color temperature. Put the photo and the color temperature chart together and you will see that the color shift is exactly the same. The left part slowly changes from the brightest solar white to yellow, orange and red. The part on the right is slowly changing from cyan to blue in the sky, and finally a little purple.

Even better, due to lighting reasons, the left two special effect lights, the left one is red light, and the right one is blue light. And because the cat is moving, but the light is not moving, so the video starts when the cat is on the left side of the video as a whole is reddish, and when it is on the right side, the overall color is blue. Now the video background modification can solve this problem. . The left side is yellow light, because the dark side will change the hue, so the color will be reddish, the right side is blue light, the dark side will become bluer or even a bit purple due to the hue change. These match exactly the lights I rendered on the cat earlier. It also perfectly solves the problem that when the video is pre-rendered, the color of the cat is reddish on the left side of the video, and the color is bluer on the right side of the video. However, I found that the color at the intersection of yellow and blue is very dirty, and the color transition between the top and bottom of the video is not perfect, so I plan to add other colors in the future. Make the whole work more colorful.

After adding the background, the next step was to color the dark sides of the clouds. Because the cloud layer is moving, and the part of the dark side is different in each frame, so I plan to add the color directly and use a soft light coating, so that the software can automatically calculate and add the color to the dark side. Does not change the white of bright clouds. And because only 1~2 layers are added, the final overall calculation and rendering will not be particularly troublesome. After all, I don’t have enough time.

https://www.youtube.com/embed/gc0_ojIWlVU?feature=oembed

When looking at the overall color effect, I found that the color at the junction of yellow and blue is very dirty, and the color transition between the top and bottom of the video is not perfect. The background of the whole video is only blue and yellow, which is too simple overall. So I plan to add additional colors in the future. Make the whole work more colorful. In the end I plan to continue adding colors based on changes in the color temperature table. The yellow part changes from orange to red according to the color temperature, and the blue part changes according to the color temperature. Finally, a perfect transition can be formed between purple and red. I turned this layer into a soft light layer and it worked really well, but because the color saturation was too high, I lowered the saturation some more to make it more compatible with the tone of the entire video.

When I finally watched the overall effect of the video effect, I found that the two layers of clouds below the video were not too far apart, so I added a gradient layer of shadow between the two layers of clouds. Enhanced the effect of depth of field and front-back relationship between two layers of clouds.

Finally, I directly dragged the photoshop format file into After Effects, divided each layer, and adjusted the layer settings. After adjusting the color of the cat through the curve to make the color more obvious, my work will be rendered finished.