Developing a 3D game(like UT, Quake, GTA3,etc)

[abdul]

What is the hardest and most time consuming part in the development of those type of 3D games that included a wide range of environment and graphics? I may be wrong but I just a surface and some buildings on it using MilkShape 3D and was able to load/show them with very few coding. I was also able to move the camera and walk around. Is that the part and collision detection which is hard/time consuming or what?

[Zaei]

Use 100 times the number of polygons to make your level, add some meshes, trees, etc, and you will find out why there are so many culling algorithms out there to choose from =). Collision detection also gets boosts from the culling methods. Add in mesh animation, user interface, etc, etc, and you will end up with a lot of work on your hands.

Z.

[SapphireGreen]

Dont forget game AI, and Pathfinding, and general Physics... and a lot of other things.

You also need to plan a Game Design Document.