Comb Ridge

This site is dedicated to sharing information, tutorials, or whatever comes to mind as something useful to write about.

Most posts will focus on 3D modeling, R, GIS, or productivity tips.

Feedback is always welcome. Leave a comment on a post or email me.


Artifact Photogrammetry Basics

Photogrammetry

Photogrammetry is a broad field that involves obtaining metrics from photographs. Structure from motion (often abbreviated sfm) is a branch of photogrammetry focused on estimating 3D structure from photos. This is usually what we mean when we say photogrammetry, and I’m happy to continue using the generic term, but now you know.


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Why I like R — web scraping and the NBA playoffs

Learning R has been fun for a number of reasons for me. One is simply that I find programming fun. It’s like solving puzzles for me. Sure there’s a lot of frustration involved, but I find it worthwhile. R has been fun because I love numbers and it’s designed for statistics. Another passion is efficiency. I don’t like to do things by hand if I have to, and I love to automate things. Today I wanted to demonstrate some of the possibilities R has to offer. Instead of something archaeology related, I’ll talk about another passion of mine–sports.

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Academic Reading on the Go — Adobe's liquid mode is a game changer


I love reading on my phone. Why? Because it is convenient. Books are great, but they usually require using both my hands, and that’s a lot of work. Even worse, I have to carry the book around. It’s been a long time since I walked around with a novel in my pocket in case I got bored. Reading on a computer is ok, but it’s not my favorite. I usually read e-books or html content like news and blogs on my phone. Keeping up with the latest archaeology articles and books is a lot harder though. I often feel like I should be spending a lot more time keeping up with the ever-growing literature. Academic books aren’t very portable, but most of my reading is done with pdfs. For a format that is literally called a “portable document format,” pdfs aren’t that easy to read on a phone. Apparently I’m not alone in thinking this:

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Making Image Mosaics in R

I had the idea to make my dad an image mosaic of his grandkids for Father’s day. My immediate thought was to check if R had a package for that–and it does. The RsimMosaic package is a great tool for making image mosaics. Combined with the magick package, I have all the tools I need. While I think the picture of my dad turned out great, I decided to make an archaeology related mosaic for this post.

Mosaic Small

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Automatic Background Removal

There are a few different ways to automatically mask backgrounds when making a 3D model using photogrammetry, but I’ve struggled to find a method that worked for what I was doing. Photoshop released a new AI feature to automatically select the subject of an image. This post explores how this tool can be used to mask unwanted background features when creating 3D models using photogrammetry. This is not a photogrammetry tutorial, and I assume a basic familarity with Metashape (formerly Photoscan), the software I use for photogrammetry.

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Tutorial: Size 3D Models in Blender

This tutorial demonstrates how to accurately size a 3D model using the open source software Blender.

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Pilling Figurines 3D Models

I was recently able to photograph the Pilling Figurines and process the images into 3D models using Agisoft Photoscan.

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