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 computer… Read More... "3D-2D Perspective Mapping in Excel – part #1"
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,… Read More... "Three-Pendulum Harmonograph #2 – an improved version"
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 as… Read More... "Game of PONG #2"
Hi folks, this is a “practice box” for pong. The green button will “Start-Stop” the model and will also link the mouse to the bat (racket) for game control . The bat control is very smooth and quick and no mouse clicking is necessary. The red “Serve” button will shoot a new ball when you loose the old one (you don’t need to stop… Read More... "Game of Pong #1 – a dynamic training box with sound effects"
Here is another example of sprite animation in Excel (Office 2007 will work fine, though a little bit slower). We’d love to hear from you. George Read More... "City Lights in North America – sprite animation"
Ladies and Gentlemen, you will like this. Here is a harmonograph in MS Excel 2003 which models a real one build by Karl Sims. Watch the video first to know what to expect. I could have built it from the bare drawing equations but that would have been too easy and no fun at all so I tried to model the… Read More... "Three-Pendulum Harmonograph (#1)- an automatic drawing machine"
Hi guys, here is an animation I made yesterday by downloading 120 pictures of the Earth taken 12 minutes apart by satelites above the equator at 30 degrees longitude west on 10/01/2010. The pictures are 500 x 500 pixels and they are pasted as a background of a chart by a slimmed down VBA macro. You can change the speed of… Read More... "Day and Night Over the Atlantic – an example of sprite animation"
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 changing… Read More... "A Speedometer in Excel"
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 visualize… Read More... "Tutorial – a Static Lissajous Emulator"
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. … Read More... "How to Make an Analog Clock in Excel"
Hi there, this is a Tetris game I made in Excel two years back. To start or to pause, click the yellow “sun” icon in the upper right corner of the chart. You can adjust the game level on the top side of the chart and also change the landscape by clicking “Landscape” on the bottom right. The landscape will… Read More... "A Game of Tetris in Excel"
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 feature… Read More... "Static VBA Macros"
Here is a 3-body system with 3D graphics. This model works at about 30 frames/second in Excel 2003 on a modern PC. In Excel 2007 it will run 10-15 times slower. I know 2010 is a lot faster than 2007. I need to add few more features. I am also thinking of adding a 3D gravitational surface map later (like… Read More... "3-Body Planetary System with Options"