With Ian Wood's Three Dimensional Graphics program you can explore and design your own 3D line drawings on the Beeb

The BBC's graphics capabilities are excellent, but to take full advantage of them you need the right software. Three Dimensional Graphics for the BBC lets you design a three dimensional line drawing which can then be rotated in any direction. You can also save and load your own programs.

1. Rotate Shape
   This brings up the rotation menu.
2. Save Shape
   If this is chosen the program asks for the filename. Be careful not to cause a 'Bad string' error (by using a CHR$ less than 32). If you are using tape, the computer will print 'Record then RETURN'.
3. Change Shape
   This brings up the shape menu.
4. Move Shape
   This brings up the movement menu.
5. Exit Menu
   This redraws the shape.
6. End Program
   If this is chosen, the computer asks whether you want to start again. If you don't, the program ends.

1. Use Demonstration Shape
   Clears the current shape and loads the built-in demonstration shape.
2. Load New Shape From Tape/Disk
   Clears the current shape and asks for the filename of the program to be loaded. Pressing RETURN without a filename loads the next program on tape.
3. Create New Shape
   Clears the current shape and enters the editor.
4. Edit Shape
   Enters the editor.
5. Change Title
   Is the only way to change the title, as clearing the shape does not. A null string may be entered. When the shape is saved, the title is saved with it.
6. Exit Menu
   Redraws the shape.

Both these give a choice of six directions plus the 'Exit Menu' option. When a direction has been chosen, the program asks how far you want to rotate or move the shape.

The movement menu also has a 'Change Camera Position' option. This is included in the movement menu because the 'Move' options actually change the camera position.

The editor is entered from the shape menu simply by selecting either the 'Create New Shape' option or the 'Edit Shape' option.

Two cursors are displayed, together with their x,y,z coordinates, and can be moved around the screen. If the space bar is pressed a line will be drawn between the cursors and if the Delete key is pressed, the line will be deleted. Note that it's possible to draw up to one hundred lines.

To move the square cursor, use the arrow keys, and 'I' and 'O' for 'in' and 'out' (away from and towards you). To move the cross cursor, shift the keys.

When the shape is finished, press Return.

The procedures and functions appear to be rather disorganised, but in fact they are in chronological order. When I thought of something new to put in the program, I just added another procedure to the end.