10. The 3D Board

Sigma Chess includes a highly realistic 3D chess board which is selected via the 3D Board command in the Display menu:

The 3D Board

Contrary to the 2D board, the 3D board contains very few graphical elements apart from the chess board itself; the philosophy being that the 3D board is used when you really want to concentrate on playing an interesting game of chess, just as if you were sitting at a real wooden chess board, without being disturbed by extraneous information - it's you, the chess board and nothing else!

You can even hide the chess clocks using the Show 3D Clocks command in the Display menu. The menu bar is also hidden until you click in the top part of the screen or invoke a menu item via a command key shortcut. Most menu commands from the normal 2D mode are still available. You can turn the board, change colour scheme and invoke the position editor. However, the Library Editor is not available in 3D mode.

The 3D board is now displayed using thousands of colors, which significantly improves the display quality over version 4.0 where only 256 colors were used. If your computer can only show 256 colors, you can still use the 3D board, but this affects the quality.

If you switch to another application or the Finder, the 3D board is hidden until you switch back into Sigma Chess in order to allow access to the Finder desktop.

Making Moves

This essentially works the same way as in 2D mode by dragging the desired piece. You can also see legal moves when it is your turn just like in 2D mode.

If you promote a pawn, Sigma Chess will show a queen, rook, bishop and knight on the side of the board. You then perform the actual promotion by dragging the desired piece to the promotion square, where the promoted pawn is blinking. If you want the Queen promotion, you can also just press the Return/Enter key.

The Position Editor

The position editor works basically the same way as in 2D mode. The available pieces are shown to the left and right of the board, and you then simply drag the desired pieces onto the board just like when promoting. The remaining buttons are placed beneath the board edge and are all text buttons.

Memory Requirements

In most other chess programs supporting 3D boards, the appearance of the pieces are the same regardless of their position on the board, which partially destroys the 3D illusion. In Sigma Chess the piece definitions are not static, however. Their appearance changes as they are moved across the board reflecting differences in both distance and perspective: not only do closer pieces look larger and are seen more from above, pieces on the side of the board are also tilted slightly outwards. This results in a much more realistic 3D look, but also consumes more memory since several images of each piece are needed. Hence the 3D board alone requires about 2 Mb in Sigma Chess. By disabling the 3D board in the Preferences dialog and restarting Sigma Chess you can free up some memory for the transposition tables (see below).