Trilinear filtering still has weaknesses, because the pixel is still assumed to take up a square area on the texture. In particular, when a texture is at a steep angle compared to the camera, detail can be lost because the pixel actually takes up a narrow but long trapezoid: in the narrow direction, the pixel is getting information from more texels than it actually covers (so details are smeared), and in the long direction the pixel is getting information from fewer texels than it actually covers (so details fall between pixels). To alleviate this, anisotropic ("direction dependent") filtering can be used. See also Bilinear filtering Anisotropic filtering Trilinear interpolation Lanczos resampling Texture filtering