#### A Legacy 3D Octal Planetary Model

04/17/2011

This is an older model of planetary motion in 3D containing eight planets. A video preview can be watched here. [sociallocker][/sociallocker]

#### How to make a game of PONG in Excel – part #1

02/23/2011

This post contains the first part of a series of tutorials demonstrating how to build a lively game of Pong in Excel. The section deals with the bat movement VBA macro, and plotting the “court” or “tennis-table”  on a 2D scatter chart. [sociallocker][/sociallocker]

#### Casual Introduction to Numerical Methods – spring-mass-damper system model – part#5

02/22/2011

In this tutorial, most of the calculations for the numerical simulation a SMD (spring-mas-damper) system will be consolidated into a single formula, the coordinate formula. In this case, in order to calculate the coordinate at the end of a any time step, we will need just the coordinates from the previous two time steps and of course the input parameters (constants). These input parameters are: mass, damping ratio, spring constant and time…

#### Casual Introduction to Numerical Methods – spring-mass-damper system model – part#4

02/21/2011

This tutorial explains the principles to generating animation for the spring-mass-damper system analyzed in the previous presentations. [sociallocker][/sociallocker]

#### Creating a Speedometer in Excel, Part #2 – tutorial

02/11/2011

The previous tutorial (first half) explained how to download a speedometer picture from www.flickr.com and how to alter it (delete the needle) using a freeware called Gimp (similar to Photoshop). – The model replaces the deleted needle from the picture with a moving one created from a chart line. – This second half of the tutorial explains the geometry, trigonometry and VBA code used to build a new rotating speedometer…

#### Creating a Speedometer in Excel, Part #1 – tutorial

02/10/2011

This is the first half of a tutorial which shows how to create a speedometer in Excel. The model is essentially a 2D scatter chart having as background the picture of a speedometer dial downloaded from www.flickr.com. Before using the photograph you need to erase the arm of the speedometer from the picture using Photoshop or other photo editing software. In the model I replaced the deleted arm with a moving arm created from…

#### A Family of Speedometers in Excel

02/09/2011

Hi guys, by popular demand, this is a file containing five different animated speedometers and a tachometer (rpm-meter). I can recognize two models: a Toyota Camry and a Ford Crown Victoria. They work great. The rest I am not sure what they are, I would appreciate if you tell me. Just leave a comment. The model works in all versions of Excel. Cheers, George [sociallocker][/sociallocker]

#### Instant 3D-2D Perspective Mapping – the Navigator Functions – a convenient pair of user defined functions

02/02/2011

This tutorial explains a pair of important user defined functions, the “Navigator_u()” and the “Navigator_v()”. These functions save the user nine columns of formulas by calculating the effects of: 3-dimenssional shift, rotations around the three axes of coordinates and 3D-2D perspective mapping. These user defined functions are also easy to use compared to writing all the perspective mapping equations from scratch. In the previous 3D perspective tutorials we took…

#### 3D-2D Perspective Mapping in Excel – part #2

01/31/2011

The first half of this presentation dealt with mapping a 3D scene onto a 2D surface which can be a computer screen, a projection screen or the retina of the eye. By doing so we preserve much of the feel of depth of the scene. Of course when we look at an picture we get only part of the feel of depth because our both eyes see the same image….

#### 3D-2D Perspective Mapping in Excel – part #1

01/31/2011

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 monitor, a screen, or the retina of the eye). This tutorial…