Monday, September 21, 2009
Wrestling with 3D
With Kelley out of town, cataloging is on hold and I am learning some new skills. Today I took a sherd from a tin glazed punch bowl (top) and turned it into a complete 3D image using AutoCAD(bottom).
The first step in the process was to create an accurate drawing of the sherd (center). Using a radius template, I found the radius of the bowl rim and the foot-ring. I measured the height as well. I then sketched the outside and inside of the bowl using these measurements and a mixture of tracing and freehand. I also free handed the painted decorations as best I could. The drawing was scanned onto the computer and imported as a 'raster image' into AutoCAD. From there I had to trace the imported image so I had a series of lines and points that could be manipulated. I made the surface of the bowl with decorations and the profile of the thickness of the bowl separate images.
AutoCAD took the profile and swung it around 360 degrees on its center axis, like drawing a circle with a compass. Add a surface rendering and there was a three dimensional image of the punch bowl as it would have looked in its entirety (without decorations and surface variations). I moved the traced decorations into place on this image and voila! Finished!
Of course in recounting this process, I have glossed over all the erasing, undoing, head-scratching, and computer defenestration. But with help from Jim, I am quite happy with the results. I will continue to tweak the image and whose knows where it will eventually end up?