OK Foxar I will see about GTA if it is legal and I already Have 3d max and SU
But till that I'm using the SU to Blender method ,
But i have a problem with collade importing inside blender
maybe my python installation or the collada blugin installation isn't right
So If some body there have an experience with that topic maybe fine
Thank you Gaius ,
I will Do So
So i think i'm gonna learn some Python scripting, maybe i will post a new topic when my game is ready
Ok, First thank you very much ( BTM, Miika1978, and Foxar )
Really satisfying advices,
But i want to mention that the main reason that make me go to sketchup is that my first game will need to be Architecturally well designed ( as i'm going to model my university as the game world ) and I dont need a lot of characters
Beside Sketchup is very easy and fun to use
so i want to know what should i do after modeling the university buildings ?
And i'm gonna PM Foxar maybe i can use GTA for that
Thanks again. 
Hello, I'm very new to SU and need help about How to use sketch up to design 3d game?
Frankly I'v never made a game and dont know the best work path or processes should i do,
so i just started modeling a little in SU, BUT dont know ho to continue to make my own game.
I'm feeling so happy dont know why 
so Thanks in advance