Weird shapes in 3D mesh models during generation typically result from mesh topology issues (like non-manifold edges or flipped face normals) or generation algorithms struggling with complex/vague inputs.
Non-manifold edges (shared by more than two faces) or incorrect normals break the mesh’s structure, while algorithms may misinterpret noisy data (e.g., low-quality scans) or unclear prompts into distorted shapes.
To fix this, use tools like Blender’s "Select Non-Manifold" to resolve topology problems or refine your input prompt to better guide the algorithm.