Tag Archives: tutorial

Book review – QGIS Map Design by Anita Graser & Gretchen N. Peterson

While finally doing my revisions and corrections on my dissertation text, I spend my last days of work (meaning work I am actually getting paid for) on maps. In our project, we are working on different names of deities and it would be nice to give a summary to all those names and – a distributional map.

So, I built the map – when there will be enough time, I hope to do a proper tutorial on that – and I collected the data and now I am sitting here in front of my screen … and I do not know how to actually design a proper map, with a layout, with a meaning. It seems rather rude to myself saying that I have not a clue how to do map design, because I am quite fit with the software and I can handle my data quite well.

I know that I need a distributional map as well as a map where I can show how many objects have been located in my known finding spots. I started googleing around on map design and then I found it: “QGIS Map Design, Second Edition (for more information click here), by Anita Graser & Gretchen N. Peterson, with new and updated workflows for QGIS 3.4.

QGIS 3.4 is the current long term release (LTR) and available for Windows, Mac and Linux. I am now working on Windows with QGIS 3.10, and there are not so many differences to 3.4, so I am quite good with it. And I have to say, it actually never crashed: 3.10 works fine as well.

But now, the review: Actually, the book is designed like one of those nice programming recipe books you may know. Its build up in three main parts: Layer Styling, Labeling and Print Map Design.

By flipping through the pages of this book it is possible to gain an understanding of the wide variety of mapping possibilities within QGIS. These pages provide in-depth, step-by-step instructions on how to create the maps shown, a variety of genereal cartographic techniques, and plenty of design inspiration. – p. 205

On more than 200 pages there is a collection of different maps and layouts, focusing on the further use of the map and the shown data. I found this book at our university library and I flipped through it in my coffee break – and I was convinced by chapter 3 that this was the book I needed desperately.

I am no tech native, I am no programmer and I am a learning-on-the-job archaeologist trying to give a proper geographic insight on our project work. A map is like a picture – it tells you a whole story and answers a certain question.

So, when getting started with the tutorials described in the book, I first downloaded the ressources accompanying the tutorials. I played around on various examples. The descriptions are step-by-step and easy to follow. As with all technical stuff, the key to understanding is reading your instructions calmly and concentrated. I was quite impressed by my results and on the next day I started immediately to try the techniques on my own data – you see a glimpse of one of my maps I am going to use for my dissertation project in the header.

I discovered a whole new world beyond the the functions of QGIS I am now quite used to. I suddenly felt a new interest in trying things and I understood the way to think and work with my data so that there will be proper and effective results.

You should have some basic training in QGIS, but there are enough ressources online and as books to get you into the material and the fun part of it. I am still impressed by the great simplicity of the explanations and the possibilities you have as a user of the whole package data you can work on.

So, from one happy noob to the world of academic warriors, especially those in need of nice map designs – try the examples and tutorials in this book! It will change your life!

Have a great time experiencing the wonderous world of QGIS!

Yours,

Astrid 🙂

Fun with SFM – part II: The results

So, hello, dear all, I am back from a very busy family weekend – and I would like to entertain you now with our second part to our SFM-tutorial!

Due to my work at University, I have the opportunity to work with Agisoft Photoscan, which is quite the same as Agisoft Metashape. You can find all the information on this software here – I am very used to it, it is very easy to work with, very easy to understand and you hae all the features collected in one software. Of course, there are other softwares, even a lot of freeware for 3D modelling – I used to work with them as well and I think, the next step will be a comparison of the different softwares by modelling the same object. I am just looking for the time to do it, because: My dissertation has to be (okay, should be) finished by December… so, time is really rare in my life right now…

But this post is all about my little Eros/Amor riding his hippocampus. You can find the information on this example here in my first post.

I opened Agisoft Photoscan and loaded all the images I wanted to use meaning all the pictures I have taken. The first step is the aligning of the images. The software searches for the same points on different photos and matches them.

Step 1: Aligning the photos
Step 2: Building the point cloud

The next step will be the point cloud – of all the points that the software could match on different photos (the best thing is that you get the same point at least out of three different directions) there will be a so-called point cloud as a result. As you can see in the second pic here, there are a lot of “noises” around my object – you can barely recognize Amor’s foot an the tail of the hippocampus.  So, the next step is to clean this mess up. You just mark all the noises around your object and delete it. Another possibility is to mask your photos before aligning them and starting to build a point cloud. Either step will take its time.

In my first post I mentioned the different directions you have to take the pictures from. Here is a screenshot of all the thumbnails of my pics, just to help you geting an idea.
And again, the front view of my model, here already “meshed”.

So, after cleaning you will get a very nice point cloud showing just your object. I just took the side view of this sarcophagus, so my object remains quite flat with no other sides.

After the last step – the finished model!
In detail and without texture the model consists of a grid that connects all the points with each other and gives the actual shape of the surface.

After building the so-called dense point cloud (you may notice the features of the relief getting clearer), we can start with the last step – to build the actual model. As you can see here, I really tried quite hard with the texture as well. The texture can be build out of all the coloring information you have in your pics. This step is not necessary, if you are just interested in the shape of the surface. Therefore, you will get better results without coloring your model, because your eyes might get betrayed by all the shades and colors.

If you want something nice to show your students or your friends, then go for the texture. 😉

Of course there are further things to do on Agisoft Photoscan/Metashape or with other software – it’s a playground, so feel free to try. And remember, I took these images with my phone camera, so no pressure on that. Of course, your first tries may suck, but hey, it’s a process. I am still learning too and I am still discovering new fascinating features and possibilities.

I hope you enjoyed this little post – stay tuned, keep calm and start 3D modelling. 🙂

All the best,

Astrid