fixed issue with model being null
fixed issue with model being null

dennis-park/OOGALoompas,jordanly/oogasalad_OOGALoompas,garysheng/tower-defense-game-engine,sdh31/tower_defense,dianwen/oogasalad_TowerDefense,codylieu/oogasalad_OOGALoompas,kevinkdo/oogasalad_OOGALoompas