关于texture filter mode.

以下为引用http://answers.unity3d.com/questions/468376/what-is-the-difference-between-bilinear-and-trilin.html中的相关讨论总结

"

for textures viewed at an oblique angle, high levels of anisotropic filtering are recommended. With bilinear filtering only, for example, if you slowly approached a vertical wall that's initially off in the distance, you would see the different mipmap levels suddenly change as you got closer. This is especially noticeable with normal maps. With trilinear filtering, the mipmap levels are blended, so it's a smooth transition instead."

另外GUI 的TEXTURE没有MIPMAP。