I entered the following in the WebODM (Open Drone Map) forum. Some of it is a bit technical for this blog, but thought it might be interesting to some people.
Just for fun, and to learn more about WebODM and Blender, I flew my DJI Mini 2 drone around my deck to create a model. My deck has trees on 3 sides of it and overhanging it. Flying between the tree branches to get some of the shots was a bit challenging. There was a bit of a pucker factor a few times when flying inches below a branch and the drone started drifting upwards! (The Mini 2 has only forward and downward sensors, which is good here – I could never have flown that close to the trees if there were active sensors the other directions.)
I shot 142 images and processed those and saw some areas that didn’t seem to have adequate coverage. So I shot another 49 images to fill in some areas. That improved the places I concentrated on, but it seemed that some other areas decreased in quality. The glass railing and adjacent sunroom windows and doors caused some oddities, as expected. One thing I found odd is that the deck and other items seem to be “reflected” in the undersides of the tree branches.
My processing system is Windows 10 Pro on a laptop with 64GB of RAM. I initially processed this using Docker/WebODM, but ran out of memory when I increased pc-quality to ultra. I then processed it in Windows native WebODM, and it processed in 24+ hours. The WebODM timer showed 36 minutes, so I don’t have accurate information…
I postprocessed this with Blender to clean up some of the extraneous parts of the model, but purposefully left most of the trees. To get the upload files under the 100MB limit for the free Sketchfab account, I decimated the model in Blender to 70% and converted the PNG files to JPG.
Click on the image below to activate the model. Use your mouse buttons to change the view, and your scroll wheel to zoom in and out. Type “F”, or click the double-ended arrow in the lower right, to open it in full screen. (I highly recommend viewing it in full screen.)
Last fall we were traveling and spent some time in the Tucson / Lazydays KOA Resort. As part of the amenities, we were given free Wi-Fi access during out stay. The Internet there is managed by Tengo Internet, which we understand loosely means “we have Internet.” Ummm. Maybe. Sometimes. I think it can be interpreted similarly to “Yes, we have no bananas.”
Yes, we had Wi-Fi. We were right across a street from the Wi-Fi antenna, and we had a good Wi-Fi signal. Having a good Wi-Fi signal is not synonymous with having good Internet. Or any Internet at times.
I found that at about 4:00 am I had decent Internet. At 4:00 pm the Internet was so slow it was practically unusable. At 8:00 pm it was so slow that my phone said I had no Internet and it switched to cellular data, at $10/gigabyte. Ouch!!
Tengo Internet had a paid option that they guaranteed would provide 5 megabits/second speeds. I paid. It didn’t help. I still essentially had no Internet connectivity at the busy times of day, and I don’t think I ever saw 5 Mb/s speeds (except maybe at 4:00 am).
After a week of this, when we were depending on having Internet available, I decided it was time to find a solution. I looked into standard mobile hotspot providers, like Verizon and T-Mobile. The problem was that you had to pay a monthly subscription fee whether you were using the hotspot or not. And since we wanted it just when traveling, sometimes for a few days at a time, that didn’t seem like a good solution. And what if the provider I chose didn’t have good coverage in the area I needed it?
Eventually I stumbled across SolisWiFi.co, at that time, SkyRoam. (Some areas of their website still identifies it as SkyRoam.) I purchased a Solis Lite WiFi hotspot, about the size of a hockey puck.
Solis Lite Hotspot
This device has a built-in battery that lasts up to 16 hours. Add an app to your mobile phone to control the hotspot and purchase Internet access, and you’re ready to go. When powered on, the Solis Lite will find the best provider to connect to, and provide you with 4G Internet. It’s not 5G. But good 4G was plenty fast enough for us.
You can connect up to 10 devices to the hotspot. That easily covered both of our mobile phones, an iPad, a laptop PC, and an Echo Dot. Range was easily 20 feet or more.
The Solis Lite worked well when sitting around camp. When we went to the pool, we took it with us. Several times we went to a picnic area in Saguaro National Park, and took the hotspot with us there. We had no cell phone service – none at all. Yet the hotspot was able to find enough signal from some carrier that we were able to access the Internet without problem.
We also carried the Solis Lite in the car when we were traveling. We typically track our trip on maps and other applications on my iPad or our phones, and that map updating can use significant data. Using the Solis Lite hotspot in the car kept us from using our expensive cellular data.
Where does it work? They say in over 130 countries worldwide. USA coverage seems to be pretty good. I don’t recall encountering any place that it didn’t work for us.
How much? The hotspot was about $125. There are several purchase plans for Internet usage. You can purchase by the megabyte, by the day or by the month (with usage caps). If you can predict your usage, the monthly plans are probably the cheapest (your mileage may vary). As I write this, a USA monthly subscription that includes 10GB of data is $40 (there are several other options). That’s $4/GB, much cheaper than my phone data plan of $10/GB (I’ll be shopping around soon…). If you exceed your monthly plan, you can add data at any time. Global plans are a bit more expensive than USA plans.
If you choose to purchase by the Megabyte, that starts at $8 for 1 GB, $35 for 5GB, $60 for 10GB, and $100 for 20GB.
The Global Unlimited Daypass is $9. Unlimited data. Anywhere. Great if you need data just for a day. You can buy these in advance (watch for sales) and activate them when you need.
Check the plans carefully. They seem to change from time to time, so don’t assume that a plan you had six months ago is identical to the plan you can get now.
Where can you get the Solis Lite? Last fall it was available from Amazon. I purchased it directly from SkyRoam, and was very disappointed in the shipping. They don’t seem to care that you might want it soon. It took several days for it to ship, and I think they paid extra to have USPS delay it for a few more days. Right now, Solis WiFi’s site says it’s out of stock. There is one left on Amazon (search for Skyroam Solis). I also found it at Target and Ebay. It’s out of stock at several other places, which makes me wonder if there is a supply problem, or if they may have stopped manufacturing that model and may be coming out with something new.
Was the Solis Wi-Fi Hotspot without problems? No. Several times the hotspot locked up with an error message in the app, and I had to power it off and back on to get it working. When I tried to change the password through the app, I found that the display was white on white – not exactly readable. At one point I had a few GB of data left in the monthly plan, and I was metering it out to avoid buying extra data to make it through the month. The plan expired many hours before the app indicated it would and I lost the remaining data. I suspect a problem in the app having to do with the difference between UTC and local time caused that, but support was unable to tell me what had happened. Overall, though, it worked well.
Note that my analysis and purchase was about six months ago. Things change quickly, so check around for other options. That said, we have been happy with the Solis Lite, and I think we saved some money on our one trip with it. There is a convenience to being able to access multiple carriers. Keep an eye on the app or the Solis website for deals. They frequently have discounts on data (there is a 30% off monthly plans right now). You can always buy data for use in the future.
This was going be be a blog about using Blender to create 3D scenes. Sort of. I’m just barely starting to learn Blender, so it wasn’t going to be anything fancy or in-depth.
But, I went down a rabbit hole. Imagine that! I started with the ASDM Rock I photographed a few months ago (see my post PHOTOGRAMMETRY: 3D Models from Photos), and was going to try to add some sunshine, and animate the sun moving across the rock, and maybe in the future create some somewhat realistic looking grass around the rock. But, I got sidetracked and decided to try to 3D Print the rock. Not at full scale(!). Just a little plastic rock I could put on my desk.
Blender
OK, so what is Blender? From Wikipedia, “Blender is a free and open-source 3D computer graphics software toolset used for creating animated films, visual effects, art, 3D printed models, motion graphics, interactive 3D applications, virtual reality, and computer games.” Did you read all of that? Free. Open Source. 3D computer graphics software. Animation.
Blender is used to create everything from 2D and 3D still pictures to full length animated movies. Wow!
I’ve known about Blender for several years (at least). I’ve looked at it a few times, but every time the learning curve scared me off. But it can do so much. And FREE, so no big investment (except my time) to play with it. After playing a bit with Open Drone Map, creating 3D models from “just a bunch of photos,” I thought maybe I should look at Blender again. So for the last 4-6 months I’ve been watching tutorials on YouTube and LinkedIn Learning, being awed by what others have done with Blender, and wondering if I could accomplish anything significant with it.
Very brief recap of my blog on Photogrammetry: I shot 40 photos with my cell phone of this cool looking rock that is located in front of the Arizona-Sonora Desert Museum outside of Tucson, AZ. I then used Open Drone Map to process these 40 photos to create a model of the rock, and used Blender to do some very minor editing to eliminate the extraneous parts of the model. I uploaded the model to Sketchfab, where you can view it in all of its 3D-ness.
Starting with this same model, I used Blender to create a base and export it to an STL file, which can be used to print a 3D model. That sounds rather mundane, but I spent many hours trying to get the initial model ready for 3D printing. Several YouTube videos later, I managed to create something that would print nicely. I also added a little sunshine to the scene, just because I could.
For comparison with the printed model, here is one of the photos in the sequence that was used to create the model.
Rock at Arizona-Sonora Desert Museum Entrance
Here is the ASDM Rock, as rendered in Blender. I added a little sunshine to the scene, just because I could :-).
ASDM Rock, from Open Drone Map model, rendered in Blender
The final result? Here is my printed “rock.” I think it rather accurately represents the original rock!
