【Physics Material】
1、 The Physics Material is used to adjust friction and bouncing effects of colliding objects.
Physicx Material是Collider的一个属性，用于设置摩擦系数和反弹系数。
2、具体参数如下：
| Dynamic Friction | The friction used when already moving. Usually a value from 0 to 1. A value of zero feels like ice, a value of 1 will make it come to rest very quickly unless a lot of force or gravity pushes the object. |
| Static Friction | The friction used when an object is laying still on a surface. Usually a value from 0 to 1. A value of zero feels like ice, a value of 1 will make it very hard to get the object moving. |
| Bounciness | How bouncy is the surface? A value of 0 will not bounce. A value of 1 will bounce without any loss of energy. |
| Friction Combine | How the friction of two colliding objects is combined. |
| Average | The two friction values are averaged. |
| Minimum | The smallest of the two values is used. |
| Maximum | The largest of the two values is used. |
| Multiply | The friction values are multiplied with each other. |
| When two bodies are in contact, bounciness and friction modes are applied individually to each agent. So, when body A has mode Average and body B has mode Multiply, then A is going to behave according to average parameters and B according to multiplied parameters. | |
| Bounce Combine | How the bounciness of two colliding objects is combined. It has the same modes as Friction Combine Mode |
3、Detail
Friction is the quantity which prevents surfaces from sliding off each other. This value is critical when trying to stack objects. Friction comes in two forms, dynamic and static. Static friction is used when the object is lying still. It will prevent the object from starting to move. If a large enough force is applied to the object it will start moving. At this point Dynamic Friction will come into play. Dynamic Friction will now attempt to slow down the object while in contact with another.
4、和Meterial一样，可以创建Physics Meterial，如下图：
参考：file://localhost/Applications/Unity/Unity.app/Contents/Documentation/Documentation/Components/class-PhysicMaterial.html