Why in the Mipmaps view objects are red when I far away from them and became blue when I come closer?
What does it mean?
It’s a way to visualize the LOD (Level of Detail) of the mipmaps being used on the textures. As textures get further away from the camera, less detail is rendered. Blue means highest LOD, while red is the lowest LOD.
http://www.graphicshardware.org/previous/www_1998/presentations/kirk/sld026.htm
If you were using the brick texture in that image, Blue in Mipmap view would mean the texture is being rendered at 1024x1024, while Red would mean the texture is being rendered at 64x64. It helps with performance. Mipmap view mode in the editor helps to visualize where the transition happens.
For more details: http://3dgep.com/texturing-lighting-directx-11/
Textures have mipmaps enabled by default, you can adjust the mip map settings in the Advanced texture settings. Also you can adjust the texture’s mipmap bias, which will adjust the distance when the transition happens.