why is my objects turning invisble?

ok when ever i press [p] some of my objects turn invisble but there not soposed to. i packed the files and saved the dynamic runtime to test my game. and then when i went back into blender to do some editing and when i pressed the [p] key the objects that was once there turn invisible… plz help.

The most common reason for objects turning invisible is the the normals are flipped. Select the object go into edit mode, select all the vertices with “a”. Then press cntrl - n.

Your normals are probably pointing the wrong direction. By default you can only see the side of a polygon the direction that the normal is facing, so if your normals are facing away from the camera, then you will not see them. You can see normals by going into Edit mode, then in the Edit buttons, select “Show Normals” (probably over toward the right side of the buttons) and specify the size of the normals. They’ll stick out like spikes from each face, showing which direction they are facing. They all need to be facing outwar on a closed mesh. If you’re using open meshes, and you want the player to be able to see the inside and the outside, then (from Object mode) enter Face mode [F key]. Select all of the faces that you want to see from both sides, go into the Edit buttons [F9] and select the one that says “Double Sided” in the UV Face buttons.

As a shortcut, on closed meshes to get all the normals to point outward, go into Edit mode, select all faces, and press [Ctrl + N] to recalculate all normals to point outside. Sometimes this works, sometimes it doesn’t.

well none of that stuff worked… here fix it your self i cant do it lol, heres the link http://www.filefactory.com/file/94d544/ the help with be thanks lol.

You’ve got some kind of wierd camera thing going on. Press number 7 on the keyboard and look at the size of your camera and how close it is to the object. I made it smaller and backed it away and it worked.

ok i moved it pretty far back and it works now. ok thanks for that tip. well can u do any thing about two center objects going through each other? like can u make it stop at the edge of the cube?

Check the camera and remove any scale from it. Scaling the camera let the culling procedures behave unexpected.