In computer graphics we often need to be able to display a three-dimensional image in two dimensions and preserve the perspective appearance. If we walk on a straight road, it appears that the road narrows with the distance. This is the perspective effect and it is a result of mapping a three-dimensional image on a two-dimensional surface (i.e. a computerContinue Reading

Hi! Here is an improved (faster and cleaner) version of the harmonograph. The worksheet has three different areas, the physical machine (a photo of the machine build out of wood by Karl Sims), the virtual machine (which is a 2D chart with a top view of a model showing the three pendulum ends, the drawing table, and the linkage mechanism which connects pendulum #1,Continue Reading

Hi there, this is a better version of Pong, in which you play with a virtual opponent. It does not have a score board yet and the opponent is theoretically unbeatable. I will be improving it further. Excel 2007 is quite slow on this one. In order to get maximum speed out of Excel 2007 make sure you zoom in as much asContinue Reading

Here is a speedometer in Excel 2003. It’s an old file and the charting wasn’t done in the most economic fashion. I used too many series while I could have consolidated a lot of the dial curves. It is still a good example of animation and displaying custom numbers on a chart. There are two VBA macros involved, one for changingContinue Reading

Hi there, this is a tutorial explaining the construction of a very basic Lissajous emulator in Excel. It’s supposed to be very easy to understand at the high school level. Good luck, George [sociallocker][/sociallocker] A Lissajous emulator in Excel by George Lungu   Introduction: Jules A. Lissajous was a French mathematician from the 19th century – He wanted to visualizeContinue Reading

Hello folks, here is a tutorial about building a clock in Excel. Enjoy! [sociallocker][/sociallocker] Building a live Excel clock by George Lungu Here are a few date and time functions in VBA: Now  : Current date and time.   Example: 7/5/00 3:16:38 PM returned by Now Date  : Current date only.           Example: 7/5/00 returned by Date Time : Current time only.          Continue Reading

Most parameters used in animations or physical models are changed by buttons called “spin buttons”. Excel is a spreadsheet but behind the table there is a engine used to automate certain spreadsheet functions. This engine can be programmed in a language with a very easy syntax called Visual Basic for Applications, in short VBA. VBA is a very convenient featureContinue Reading