Bumarin is a Blender add-on that enables users to draw 3D meshes using Grease Pencil strokes. Designed to mimic traditional clay sculpting techniques, it allows artists to build shapes step by step by drawing and stacking individual pieces of digital clay. The toolset includes three specialized pencils for generating various 3D volumes and blocking in fundamental shapes. Additionally, it features a muscle fiber generator designed for anatomical modeling, which converts simple tube forms into bundled muscle structures.