Some things in this category include the camera , model properties , lights , particle system physics , playing sounds , playing music , handling input , changing levels , collision detection and response , and placement of 2d graphics for a heads up display , title screen or whatever 在這個范疇里包括攝象機(jī)、模型屬性、光照、粒子系統(tǒng)物理、播放聲音、播放音樂、處理輸入、改變關(guān)卡、碰撞檢測和響應(yīng),及2d圖形的放置以實(shí)現(xiàn)一些覆蓋內(nèi)容的顯示、標(biāo)題屏幕等等。