i designed a hallway with rooms connected to both sides with a ceiling and floor also i put material on them and textured them so i exported them to unity using the embed media so now when i look the hallway with the rooms connected on the top view everything is cool you can see the rooms when you walk inside and the ceiling and floors but when i play it in the game on the bottom view it only show the hallways and textures so when i walk into a room i fall through and the ceiling is now missing did i do something wrong the collide button has been checked for the model i imported in. and also when using maya the textures i put stretched and their looking a little blurry on my walls i downloaded big or medium pics from cg textures should i have used small pic downloads to get a better quality texture newbie needs help lmao 
oh yeah also the textures in maya look okay but when imported to unity their blurry any help?