why it comes like this???
The edge of your texture contains black/green, and when mip-mapped, the sides of this texture are bleeding onto the rendered output due to the texel calculation during compression.
To prevent this, increase the padding area of your texture, and try to use the most common color for the background of your texture, rather than (say) black.
At each mipmap scaling, each square set of 4 texels becomes 1 texel (average of the four), and the texture becomes more and more filtered. What you don't want is for that filtering to bleed color between each seperate UV island. Subdividing the texture using the above rule minimizes such inter-island bleeding. On the other hand, efficient use of the texture is as important as minimizing mipmap artifacts. And such mipmap bleeding is only noticeable if the colors of the inter-bleeding islands are different. Things on neighboring islands that will have similar texturing, therefore, can ignore the above rule, specially if they are continuous on the mesh itself - as in, the two islands being just the result of a seam separation.
Last edited by Rocket; Mar 30 2012 at 11:00.
"He will come to death. An image of the splendor of the kings of men in glory, undimmed before the breaking of the world."