At this moment only one floor can be present in 3DTop and is therefore always present. You might already have noticed that right-clicking on 3DTop while no object is selected will pop-up a menu with some general items. Among these are the two for the floor:

- Floor texture.
When you choose this item you can select a Windows bitmap as a texture. No constraints are put on the size or number of colors by 3DTop, but be careful that some drivers (TNT) can not handle textures bigger than 512 x 512 pixels.
After you've chosen a texture the following sub-menu's will appear:

- Off
When you've chosen a floor-texture you can switch it off with this item.

- Tiles
Checking this one will make the texture tile on the floor.

- Load other...
When you choose this item you can select another Windows bitmap as a texture. No constraints are put on the size or number of colors by 3DTop, but be careful that some drivers (TNT) can not handle textures bigger than 512 x 512 pixels.

-Edit floor-size and tiling...
This will enable you to choose the size and tiling (when you have "Tiles" checked) of the floor. You'll notice that the mouse-pointer changes its shape into a left/right/up/down arrow, this means that by moving the mouse left or right you change the size and by moving the mouse towards you or away from you, the number of tiles can be changed.
When you change the number of tiles you also change the way that lights light up the floor... A low number of tiles means a lower accuracy but increaces the drawing speed of the floor.
When you are content with the size and tiling you've chosen, press the left-mouse-button once and the floor holds that size. If you would like to cancel the whole operation press the right mouse-button once.

Be careful, the tiling-accuracy of the floor can have a dramatic effect on the speed of 3DTop. When the floor is extremely large it can slow 3DTop down considerably.

A tip: Bitmaps are internally stored in OpenGL with a width or height that is a power of 2. So if you have a bitmap with the size of for example 312 x 260 it is stored with a size of 512 x 512. This is not very effective in terms of memory-usage. It is best to resize the bitmap to say 256 x 213 and create the floor-texture with this resized bitmap, this causes the bitmap to be stored as a 256 x 256 bitmap.
Power of two is: 2 , 4 , 8 , 16 , 32 , 64 , 128 , 256 , 512 , 1024 , 2048 etc.