* Exaggeration for comedic effect: Animation often relies on exaggeration to create humor. A character smiling in pain can be funny, especially if the injury is over-the-top or silly. Think of a cartoon character getting hit with a hammer and still smiling, even though their head is now flat.
* Conveying resilience and strength: A character smiling in the face of adversity can show their strength and determination. It can also make the character seem more likable and relatable, even if their situation is painful.
* Simplifying emotions: Sometimes, animators choose to simplify emotions for clarity and visual appeal. A smile can be a quick and easy way to convey that a character is experiencing some kind of emotional response, even if it's not necessarily happiness.
* Aesthetics and style: Certain animation styles, like the exaggerated style of early cartoons, often use broad, stylized expressions. A smile might be the chosen expression for a character in pain, even if it doesn't make sense logically.
* Avoiding disturbing imagery: Showing realistic pain can be upsetting to young viewers. A smile can soften the impact of a potentially violent scene, making it more palatable for the target audience.
It's important to remember that animation is a form of storytelling and visual communication. The choices made by animators are often guided by the specific needs of the story and the desired emotional impact on the viewer.