Month: October 2022

When I continued to search for relevant information, I found that the hair made by Houdini might not be imported into Unity, so I made two plans. The first plan is, if Houdini’s hair can be imported into Unity, then make AR animations as originally planned. The second plan is that if Houdini’s fur can’t be imported into Unity, then I’ll render the furry cat animation. Just render the cat, then add some backgrounds drawn by yourself, and use AE to animate your drawings. I studied 2D animation in college, so I know how to draw and I know how to animate them using AE (Adobe After Effects), which is not difficult for me. And there are a lot of movies, like Spider-Man: Into the Spider-Verse, 2018, and Arcane, 2022 that use painted backgrounds to save money and time.

I did a tour around the UK with a tour group during the holidays, and when I visited the Isle of Sky in the Scottish Highlands with the group, I saw awe-inspiring sights. A large number of clouds floated on the sea in place of seawater, like rolling waves. A rainbow is formed because of the humidity, hidden in the clouds, standing on the high ground, and looking at the canyon as if you are in the clouds. This beautiful phenomenon is so rare that it doesn’t even happen more than a week a year and I am amazed at just being able to see such a sight. I want to put it in my graduation project. I named it the cat on the cloud. The video I’m going to make is a cat walking around and sitting at a computer at the end. After I made the fur, I just need to render the cat, the cloud and fog effect can be made in AE, and then add the background and rainbow, it is also a complete work.

This photo was taken on the Skye Island in Scotland. The bottom is the sea and the clouds are above. The bright arc in the picture is the rainbow. Although it cannot be seen in the photo, if you wear sunglasses that can see polarized light, you can Clearly see the colors of the rainbow.

My next task is to make cat fur. Because the model of the bound cat I found has no fur, so I need to make the fur myself. The software I choose to make the fur is Houdini, because the fur produced by this software is very realistic, and it can even Simulates collisions between hairs. But his difficulty is also very high. Although it is also a 3D software, it is more inclined to control the nodes. The thinking and methods of this software are different from traditional 3D software, such as MAYA. Houdini’s way of thinking is more programming. There are many teachers in the school who know Houdini, but they don’t know how to make hair with Houdini. So all I can rely on is myself. This is a very big challenge. And there are often unexpected problems that occur. For example, the unit of Maya is meters, but the unit of Houdini is centimeters, so when I import the model from Maya to Houdini, I need to increase the model by 100 times. Because I didn’t know this at the beginning, the hair produced a different effect than it should, which added a lot of trouble to me. It also took me longer to make my hair than I expected.

Unfortunately, at the beginning of September, my hair reached the neck and the most complicated head was done, because the Ragdoll is a longhair cat, and its cheeks will be longer and the inside of the ears will also be It has long hair, so it needs to be made in 3 to 4 times. That is to say, it takes 3~4 strings of nodes to complete the hair production of the head. The back part of the body and tail is very simple. I had expected to finish making the hair by the end of September. But the school’s computers were overhauled in September and were not open for use until the end of September. And by the time I started using the school computer at the end of September, the Houdini software was not found in the library of the school computer. Although Houdini can be seen in Curry later. However, other students who use Houdini said that the school’s Houdini is not stable enough. Some computers can be successfully installed, some computers cannot be installed, and some libraries are not even available. So I had to change the software that made the fur and recreate the cat’s fur. After considering different software, I ended up going to use Maya’s X Gen to make the hair. Since my animations were made in Maya, it would be easier to continue making the fur in Maya without having to worry about any compatibility issues. And luckily the hair making in Maya is much easier than Houdini and can be done on time.

Model’s unscaled hair.

Model with 100x magnification of hair.

In the animation stage, first I refer to the animation principles of some 2D quadrupeds. Woods S. THE ANIMATOR’S SURVIVAL KIT[J]. Film Ireland, 2002. This book is very useful. Although research on the principles of animation of quadrupeds in 3D is difficult to find, the 2D aspect is very complete. So I referenced a lot of information in this area, and based on these materials, I made animations of walking and running of quadrupeds. Although when I started animating, I found that my cat didn’t walk or run like that at all.
However, the animation principles part of this book is very useful, and this is also a must-learn course for all animation majors.

The animation part is divided into three parts. I animate the cat’s body part first, then the cat’s ears and tail, and finally the cat’s expression.

The whole animation The animation process was more difficult than I thought, because the cat’s movements are very large, but the cat hardly has any repetitive movements. Moreover, the cat’s movement speed is also very fast, which is very difficult for me to make animations. Sometimes I need to K several poses per second.

And cats have a very special bone structure. Studies have shown that cats have wider vertebrae with elastic fibrocartilage interspersed between the vertebrae, which makes cats more flexible. This body structure makes cats more flexible than big cats. Second, they can rotate the spine 180 degrees, while humans can only rotate 90 degrees.
Because the cat’s reaction ability is very fast, the cat’s action frequency is fast and the amplitude is large, so it has caused great difficulties and troubles in the process of making animation.

There are several poses in a second. Mochi’s body often twists from an S-shape to an inverse-S-shape within a few frames because the core of the controllers is on his butt, and if you adjust one of them, the others follow. So while range of motion doesn’t seem to matter, all of the body’s controllers need to be adjusted. Also, it’s much harder to animate a 4-legged animal than a 2-legged human. The time it takes for each of his feet to fall and lift is different. These all require frame-by-frame, controller-by-controller adjustments.

And for the convenience of animation production, I chose the tail and ear parts to form a lot of mels, and the tail to form two mels. First the whole tail is one mel, then the second half of the tail is another mel, so it’s a lot easier for me to animate the selection controller.

It should also be noted that because what I want to make in the end is the AR effect, I need to see this animation from different angles. It is very perfect, and there will not be any strange places, so I put it when making the animation. There are three cameras, front, side and back. When you take a screen shot later, you can easily observe it from multiple angles to see if there are other bad points, and it is also easy to modify.

I originally planned to combine three screen shots from different perspectives into one video for broadcast, but because the screen shot was imported into the software, the report was wrong, so I divided it into three uploads.

body animation

ears and tail

expression

After determining that my project needs to animate from a video, the first thing I do is storyboard, which is very important because making any video starts with a storyboard. But because of the reference video, the storyboard is very easy to complete. Because my reference videos are fixed shots and my main work is animal behavior research. So I didn’t plan to make complicated shots for the storyboard either. And because there is a reference to the action of the video for reference. The entire video content is very simple and not long, but some editing is required. First of all, Wan Cheng started to bite the screen immediately after sitting on the computer keyboard, so the part of the screen biting at the back of this video cannot be used and needs to be cut off. However, because the entire video is only 15 seconds in total, the time of the video after cutting out the clip that bites the screen is too short, so a part needs to be added in front.

So I found another part of the video, Moqi stepped on the keyboard from my computer, walked over, then walked to the coffee table next to it, and finally turned around and walked over. In this video, Moqi kept walking, but did not sit on the computer in the end. However, because the final landing point was on the coffee table on the right, it just happened to connect to the part of the video where Mo Qi was sitting on the computer keyboard. So I put these two videos together. Of course it’s not just a matter of getting it together. When I walked at the last moment, Wan Cheng turned to the right in the video of walking over, but the video of sitting down turned to the left. So you need to pay attention when making this part of the 3D animation. And in the first video, Mo Qi was sniffing the place behind the computer for a long time. This is a cat’s habit. The cat’s sense of smell is very sensitive. When he goes to a new place or is curious about something, he will smell it first. And when you greet your cat, let him smell your hand first. But it was almost stationary for a while, and Moqi’s head was not aimed at the camera, I can’t be sure of his expression, although I can look for other videos of cats smelling things as a reference, but I’m not sure if it can match my cat. So I plan to delete this part as well.

The full version of the video, this video is more than a minute long.

The video of the cat walking around on the computer is added to the front to increase the duration.

In the end, the video clip of the cat sitting on the computer was unusable because it started to bite the screen, and because the above video turned to the right, this video turned to the left, so you also need to pay attention when making animations.

Below is the storyboard.