Material3D

描述：

  由 Model3D 实例持有的逐实例材质槽。

alphaMode

类型： 成员变量。

描述：

  透明模式：0 不透明，1 遮罩，2 混合。

签名：

alphaMode: integer
	alphaCutoff: number
	setBaseColorTexture: function(self: Material3D, texture: Texture2D)
	clearBaseColorTexture: function(self: Material3D)
	setMetallicRoughnessTexture: function(self: Material3D, texture: Texture2D)
	clearMetallicRoughnessTexture: function(self: Material3D)
	setNormalTexture: function(self: Material3D, texture: Texture2D)
	clearNormalTexture: function(self: Material3D)
	setEmissiveTexture: function(self: Material3D, texture: Texture2D)
	clearEmissiveTexture: function(self: Material3D)
	setOcclusionTexture: function(self: Material3D, texture: Texture2D)
	clearOcclusionTexture: function(self: Material3D)