Let's talk about the artistic reasons first-the mouth drawn according to reality can only show half the side face of the character, while the comic style is completely complete. The key difference is that many cartoons are flat animations, which means it is easy for the audience to feel too flat. Unless the plane is carefully made and the light and shadow are over-expressed, it means that the production cost has increased sharply, which is not complicated for the face of the character. Generally, only nose and shadow are produced. In order to solve this contradiction, the only thing that can change the character's facial features is the mouth, and the lateral deviation of the mouth can make up for the flat defect of plane animation.
And relatively speaking, in order to fully show the facial movements, expressions and personality of the characters, the advantages of cartoon exaggeration are obvious, and we don't hate it. Also, once you draw half according to reality, the mouth of the character may not look good. Because of the oral structure, the mouth is "wide open". If you exaggerate, no one will like a big mouth that looks incomplete. Technology is also very particular-if you look at the animation carefully, you can find that the outlines of all characters and objects are closed, not purely painted, or there is no clear infinite extension line. This is done to facilitate coloring, but also to control the constantly moving mouth, and it is not easy for us to misunderstand the facial expression of the character because of the inevitable slight size difference of the mouth during animation. Therefore, for the realistic "half mouth", the comic-style full mouth has the advantage of simple technology. Starting from the reality of life, it would be better to take more outdoor photos, or to find pictures for reference directly from the Internet. Generally, clothing advertisements or people's photography works will involve more. There is also drawing lessons from other people's painting style and composition skills from comics and animation works. The key lies in the accumulation of experience. I wish you a happy creation!