You did not understand what they meant. It is easier to see problems, bottlenecks, workflow issues and show stoppers or the power of the scene management, if you make a game. It does not have to be a pretty game, but it should be a complete game project.
THANKS YOU!!! finally some1 sees what i meant... for example, remake a scene from a current gen game.. not a big scene, they cant try to make just any game because as we know gs can handle casual titles greatly...
-torque remade a scene from gears, doesnt look as great but am sure they found their limitations by doing that...
OR take some props from dexsoft and throw them into a scene with some shaders, then they'll kno the limits and what needs to be tweaked
