If I change size or minimize my window, then all my objects lose their rotations and translations and goes back to it’s origin state.
How do I fix this?
The reason might be that you reset the modelview matrix (load identity) when the size of your window is changed… You should post part of your code…
If you are using glut, you should setup the initial modelview matrix in a separate function, and only change the projection matrix in the reshape function. You are probably (re)setting the modelview matrix in the reshape function too, like Eric said.