Video: 0075_assemble_puzzle_1
Phase transition: merge
State before: solid:non_particulate:rigid body
State after: solid:non_particulate:rigid body
Object: In the process of assembling the puzzle, the black puzzle piece which at the bottom left corner in the initial frame
目标物体: 在拼图过程中，位于初始帧左下角的黑色拼图块