Well, after weeks of frustration using a “generic” human hand mesh, I decided the best way to go forward would be to get a scan of my right hand to model to. To do this, I spent part of a morning last week creating a cast of my hand using Alginate (Dental mold matl.) and creating a mold and then pouring plaster into it. Alginate is a great “impression” material for creating quick molds but the down side is that you need to work very quickly and it only has a mold “shelf-life” of about 3 to 4 hours. Of course, you can only do a one-off cast. In any case, it’s perfect for what I want. You can get it a art supply stores or you can talk to your dentist to see if they would sell you some. I have a dentist friend who supplies me. This stuff sets up in a matter of a few minutes (I mean like 3 to 4 minutes max!) to slow down the set time, use ice water.
After making the mold, I quickly mixed up some Plaster-of-Paris. I poured it into the mold and let is set for about an hour. I then removed the mold box and peeled away the Alginate material. With a little cleanup to the cast using an Xacto knife to scrape and sculpt, I finally had an accurate representation of my hand to scan. Now with the cast, I create a number of black, red and blue dots on the cast called “correspondence points.” These are necessary for when it comes time in the ScanStudio Software to align the various scan passes together. I placed it on the Next Engine Scanner turntable and set it for wide mode (15 to 17 inch – shoebox size object) at quick, low-res and a 9 pass turntable scan. I also did a 3 pass bracket of the thumb. After a few more hours in ScanStudio, I cleaned up the meshes, aligned them and knitted them together. I then brought in an .scn file into SolidWorks with the image map (texture of correspondence dots) which is very useful along with the mesh to model to.
Now I have an accurate mesh to reference to in SolidWorks. Because I have the ScanTo3D add-in. I can directly reference (snap to) the mesh when I sketch 2D or 3D entities on it.
Mold box for hand
Alginate Mold ready for plaster pour
Pouring Plaster into mold
Final cast of my right hand
A perfect copy of my right hand
Scanning Cast with Next Engine Scanner
Scanned mesh in SolidWorks