I have recently needed to scan an old part that I must reverse engineer. I have used a lot of marker dots - probably over 300 as this part is large and has many flat areas that don’t scan well in feature mode. I’d like to report my findings of how I finally am starting to get reasonably good at this:
First of all, when people say you need a lot of markers in marker mode, BELIEVE IT. You do. If you think you placed enough markers, use twice that many. Your part will have a lot of dots on it. The markers aren’t that expensive and if you don’t use enough you will have a bad time. People have given tips on how to use feature mode. But, for me this wouldn’t work because the part is so big that I would nearly never be able to get things like crumpled paper into the shot properly. I’ve tried placing random stuff on parts like bolts and nuts and that can help in feature mode. But, if you find yourself needing to go to that extreme then maybe marker mode really is the way to go. Marker mode used to really be a pain to use but in recent versions it works well.
Take your time and scan slowly. It takes some practice to get good at it. Don’t be discouraged at first. Your initial scans will look like garbage until you improve your technique. This is the same as anything. Nobody starts playing guitar like Van Halen. As you develop techniques your scans will improve.
Try to scan as much as you can in a single pass without over scanning areas. Trying to stitch multiple scans together is possible but fraught with more potential for problems.
Over all, I really am impressed with the way the new version 5 software is turning out. V4 really didn’t do it for me. V5 just keeps getting better and better. 5.2.4 is pretty good! Usually merging meshes works fine. Doing Fusion works well. The isolation and overlap functions work well and really help. One of my biggest problems in the past had been that marker mode would sometimes freak out and start to do the same lost tracking, going insane style antics that you see in feature mode if it loses track of the features. This would leave garbage all over the place. The 5.2.4 version will nearly never do that and seems to essentially quit capturing frames if tracking is lost. BRILLIANT! This works really well and allows me to keep going even if I accidentally lose tracking and mess up where I’m pointing at. It makes things so much easier than in the past.
Overall, good stuff, keep up the good work on the software! It’s turning out great.