Which animation principle emphasizes the importance of weight, volume, and the illusion of 3D space?

The principle that emphasizes the importance of weight, volume, and the illusion of 3D space is solid drawing. This principle is foundational in creating believable characters and environments in animation. Solid drawing involves ensuring that characters maintain a sense of weight and presence within the scene, helping the audience perceive them as three-dimensional objects, despite being depicted on a two-dimensional surface. By effectively conveying volume and mass, animators can create performances that feel more dynamic and authentic, enhancing the overall impact of the animation.

This principle is vital for animators as it ensures that characters do not appear flat or lifeless but instead have depth and realism. Techniques employed in solid drawing include using proper perspective, light, and shadow to create the illusion of form and space. This careful consideration of weight and volume allows for more engaging and compelling animated sequences.