Photogrammetry has incredible potential in archaeological research and education. However, despite Agisoft PhotoScan’s relatively simple initial workflow, things get complicated pretty quickly. Those of us using the program tend to learn by solving problems as they occur, but this is a very piecemeal, time-consuming, and often frustrating process. Currently, anyone getting started with the program must either go through the same thing, or find someone to offer guidance.

In this series I will assemble all the separate tips that I have learned or found into a step-by-step guide on the basic process (posted weekly). I do not consider myself an expert in PhotoScan. If you are familiar with the program and have any corrections or additions, please let me know.Each week, the previous step will be edited to include any comments and placed under the “Resources” menu to serve as a guide for beginners.

The previous steps can be found here.

Step 5: Building the Dense Cloud

Now that PhotoScan knows what points you want it to work with, it is time to ink in those lines. Go back to your “Workflow” drop-down menu and select “Build Dense Cloud…” Another window pops up. In the new window, the drop-down menu next to “Quality” will let you chose the (you guessed it!) quality of your dense cloud. I switch between “High” and “Medium” myself, but steer clear of “Ultra High” unless you have a really beefy computer.

dense-cloud-windowUnder the “Advanced” section you will find “Depth Filtering.” This is all about removing outlier points. If you have, and want, lots of fine detail in your model, choose “Mild” from the dropdown menu. If you are making the model for 3D printing, or do not care about small details like a crazy person, select “Aggressive.” Click “Okay.”

That is all for Step 5! I told you the rest was simpler. The progress window will pop up and will take anywhere from an hour to several hours to complete.

3 thoughts on “The Basic PhotoScan Process – Step 5

  1. I can add one thing to Step 5. You can further reduce points once the dense cloud is produced by going to tools/dense cloud/Reduce by Color. I usually start with white and black and gradually increase the tolerance level. Hope this is helpful.

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    1. Good tip! I will get that added when it goes to the page next week. I have occasionally had the program think that the background color was attached to the model (usually at a corner), have you used this method for cleaning that up?

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      1. Yes, when I am working with an object with narrow projections or a spear point I get background colors attached to the edges. This tool doesn’t get it all, but decreases it significantly. If you go too high on the tolerance, it starts effecting the object itself. Glad this was helpful. The gradual selection on the sparse cloud helped me out quite a bit. Don’t know how I missed it.

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