官网地址：https://material.io/guidelines/material-design/material-properties.html

Material has certain immutable characteristics and inherent behaviors.

Material拥有某些一成不变的特点和固有的行为。

Understanding these qualities of material will help you manipulate material in a way that’s consistent with the vision of material design.
理解material的这些特质，能够帮助你以符合material design的一贯视觉效果去使用material。

Material characteristics
Material的特点
Solid 立体
Occupies unique points in space 占用空间中的唯一点
Impenetrable 不能穿透的
Mutable shape 可变的形态
Changes in size only along its plane 只在水平方向上改变大小
Unbendable 不能弯曲的
Can join to other material 可以结合其他才是
Can separate, split, and heal 可以分离，可以拆分，也可以复原
Can be created or destroyed 可以被创建或者销毁
Moves along any axis 可以沿任意轴移动

whatismaterial_materialproperties_physicalproperties_thickness_01_yes.png

Contents
Physical properties
Transforming material
Movement of material

• Physical properties 物理性能
  Material has varying x & y dimensions (measured in dp) and a uniform thickness (1dp).
  material拥有不同的x&y（以dp为单位）和一个均匀的厚度（1dp）

whatismaterial_materialproperties_physicalproperties_thickness_01_yes.png

Do.(官网视频)
可变的
The height and width of material can vary.
Material的宽高是可变的。

whatismaterial_materialproperties_physicalproperties_thickness_02_no.png

Don't.（官网视频）
不可变的
Material is always 1dp thick.
Material总是1dp的厚度

Material casts shadows.
Material投射阴影
Shadows result naturally from the relative elevation (z-position) between material elements.
阴影自然而然来自于Material元素之间的相对高度（z-位置）

Do.（官网视频）
Shadows depict the relative elevation between material elements.
阴影描述了material元素之间的相对高度

Don't.（官网视频）
Shadows are never approximated by coloring material.
阴影永远不与material的颜色相近

Content is displayed on material, in any shape and color. Content does not add thickness to material.
在material中显示的内容，可以使任何形状，任何颜色。内容不会增加material的厚度。

Do.（官网视频）
Material can display any shape and color.
Material可以展示任何形状和颜色

Content can behave independently of the material, but is limited within the bounds of the material.
内容可以在material的限定范围内独立运作。

Do.（官网视频）
Content behavior can be independent of the behavior of material.
内容的表现可以独立于material的表现

Material is solid.
Material是立体的
Input events cannot pass through material.
输入事件不能通过material。

whatismaterial_properties_physical3.png

Do.（官网视频）
Input events only affect the foreground material.
输入事件仅仅影响前景material。

whatismaterial_properties_physical4.png

Don't.（官网视频）
Input events cannot pass through material.
输入事件不能通过material。

Multiple material elements cannot occupy the same point in space simultaneously.
多个material不能同时占用空间中的同一个点。

whatismaterial_properties_physical5.png

Do.（官网视频）
Using elevation to separate material elements is one method of preventing multiple material elements from occupying the same point in space simultaneously.
使用高度分离material元素是防止多个material元素同时占据相同点的一种方式。

whatismaterial_properties_physical6.png

Don't.（官网视频）
Multiple material elements cannot occupy the same point in space simultaneously.
多个material不能同时占用空间中的同一个点。

Material cannot pass through other material.
material 不能通过其他material。
For example, one sheet of material cannot pass through another sheet of material when changing elevation.
例如，当改变高度的时候，一个material的薄片不能通过另一个material的薄片。

Don't.（官网视频）
Material cannot pass through other material.
material不能通过其他的material。

Transforming material
改变material
Material can change shape.
material可以改变形状。

Material can change shape.
material可以改变形状。

Material grows and shrinks only along its plane.
material仅仅沿着它所在的平面增长和收缩。

Do.（官网视频）
Material grows and shrinks only along its plane.
material仅仅沿着它所在的平面增长和收缩。

Material never bends or folds.
Material从来不弯曲或者折叠。

Don't.（官网视频）
Material never bends or folds.
Material从来不弯曲或者折叠。

Sheets of material can join together to become a single sheet of material.
material的片断可以一起集合成单个material片断。

Multiple sheets of material can join together to become a single sheet.
material的多个片断可以一起集合成单个material片断。

When split, material can heal. For example, if you remove a portion of material from a sheet of material, the sheet of material will become a whole sheet again.
当分裂开时，material能够恢复如初。例如，如果从material的片断中移除了material的一部分，material的片断将再次变成一个完整的片断。

Material can split and become whole again.
Material能够裂开并且再次汇聚成一个完整的material。

Movement of material
material的移动
Material can be spontaneously generated or destroyed anywhere in the environment.
material可以在环境中的任何地方自发产生或者销毁。

Material can be spontaneously generated or destroyed.
Material能够被自发产生或者销毁。

Material can move along any axis.
Material可以沿着任意轴移动。

Material can move along various axes.
Material可以沿多个轴移动。

Z-axis motion is typically a result of user interaction with material.
Z轴运动通常是用户与material交互的结果

Z-axis motion prompted by user interaction.
Z轴运动展示了用户的交互。