is there any way to simulate only objects which place in specific region such as around of the main character . in other words how can limit simulation for only objects that place in a specific place .
You could try making objects that are not near the player static, and then when the player is close enough make them dynamic?
IE: Get all objects near the player, make them dynamic. As the player moves, get a second list of all objects near the player. Make the whole first list static, and the whole second list dynamic.
You could probably optimize that better but it might be a good starting point
Yeah, switching dynamic - kinematic.
You can also try PxScene::addActor/removeActor.