出现这种情况是因为模型用了双面材质，而Unity不支持双面材质。故导入模型到Unity中，会出现一面有贴图，另一面透明的情况。
解决方法：
1、自定义一个双面材质Shader，代码如下：
Shader "Nature/Vegitation Vertex Lit" {
Properties {
_Color ("Main Color", Color) = (1,1,1,0)
_SpecColor ("Spec Color", Color) = (1,1,1,1)
_Emission ("Emmisive Color", Color) = (0,0,0,0)
_Shininess ("Shininess", Range (0.01, 1)) = 0.7
_FrontTex ("Front (RGB)", 2D) = "white" { }
_BackTex ("Back (RGB)", 2D) = "white" { }
}
SubShader {
Material {
Diffuse [_Color]
Ambient [_Color]
Shininess [_Shininess]
Specular [_SpecColor]
Emission [_Emission]
}
Lighting On
SeparateSpecular On
Blend SrcAlpha OneMinusSrcAlpha
Pass {
Cull Front
SetTexture [_BackTex] {
Combine Primary * Texture
}
}
Pass {
Cull Back
SetTexture [_FrontTex] {
Combine Primary * Texture
}}}} 2、在模型材质里更改的Shader为上面这个Nature/Vegitation Vertex Lit的这个自定义shader即可。
