Using autoshape freeforms is a very easy way to duplicate object outlines from pictures. It is convenient to create a freeform and once created, its vertices (points) can be edited with without difficulty. Aditional points can be inserted and others can be deleted. This is a tutorial about a series of macros which allow the extraction of freeform vertex coordiantes to a worksheet range in Excel. These coordinates can be later employed to create 3D wireframe objects for various models.

## This article has 2 Comments

Comments are closed.

Peter,

Interesting thoughts. Unfortunately I am on the run these days and I picked up the subject in order to build my 3D RC controlled airplane for one of the next topics. It took me a whole evening to find how to do the vertex retrieval. I offer this “as is”. Bezier curves are not in my colimator yet. In 2003 the regular 2D scatter charting of few hundred of vertices is lighting fast and I found out that the curves look reasonably good with or without smoothing on (soon I will post a Lisa Simpson example). In 2007 the charts are better looking (including the plot lines) but the program is slow. I hope to post a 3D canoe by tonight. George

George

It is interesting that you have chosen to start the tutorials on shape with the very versatile but somewhat complex freeform shape. Life gets still more interesting when some of the vertices are used as intermediate control points to give Bezier curves. It is hard for a scatter chart to render such shapes (how to generate points on a single Bezier curve could be the subject of a complete posting).

Converting the freeform to a scatter chart illustrates the basic points well but that begs the question of whether it is better to exploit the freeform to convey information to the user. I started developing an Excel workbook to act as a front end to a panel buckling program. Ultimately I abandoned the scatter charts which I originally used to sketch the cross-section of a stringer-stiffened panel in favor of using the freeform shapes directly.

What I do not have any feel for though is the relative speed at which Excel renders charts and the equivalent shape objects.