Impact is a powerful and flexible material-based interaction system for producing interactions such as audio, particle, and decal interactions.是一个强大而灵活的基于材料的交互系统，用于制作音频、粒子和贴纸等交互方式
PHYSICS INTERACTIONS
• Play audio when physics objects collide with each other with sounds based on the collision velocity and the objects' materials.
• Play sliding and rolling sounds.
• Emit particles on collision.
• Leave decals behind on collision.
• Works great with rigidbodies connected by joints as well as ragdolls.
