Q: I have been around and around trying to get the flat mirror reflection to work on a boxtop. Been through the manuals and the tutorials. Works just great on a cylinder top but not the box. Anybody run into this or have any ideas?

A: As you probably know from the manuals, flat mirror should be applied only TO COPLANAR FACE SETS. In your case, you have to do the following:

1. In the Material Editor, create the mirror material.
2. Create a copy of the material and turn the flat mirror OFF. Change the name of this new material.
3. Assign the non-reflecting material to the whole object. If mapping coordinates for a texture are needed, apply them.
4. Go to Select/Faces and using Window option select the top of the box.
5. Make the reflective material current. Use Surfece/Material/Assign/To Faces, activate [Selected] and apply to the selection of the top.

You get a whole box having the same material, with the upper part having a reflective version of the same material.

If you assign the flat mirror on the Object level, 3DS will use the first face's normal the renderer encounters for the mirror alignment. This means that one side of the box will reflect, but it might be not the top :o)

If you need a flat mirror on EVERY side, you will have to select them one by one, and DETACH them as separate objects... You may not attach them anymore to each other!!! (But you can link them in the Keyframer to work as a whole).