i wonder if you have an idea how to fix this … i want the texture look nice on the outside as on inside…
i tried to flip the normals - no success
i tried to turn off mipmaps by not using either gluBuild*/glGenerateMipMaps or glTexParameteri GENERATRE_MIPMAP - no success
i understand what you mean, but it still makes no sense to me, since there is no change when i try to modify the projection by narrowing/widen the focallength, scenescale, other perspective parameters…
Backface vs. frontface does NOT affect texture quality.
Your latest image did not work, I get a permission error reading it.
When you are inside the sphere your FOV is wider and the “red spot” is smaller on screen so you to not see magnification artifacts from individual texels as rectangles.
You could try to use GL_LINEAR filters for magnification and minification filters instead of GL_NEAREST.