3D Modeling Streets and Terrain

I previously wrote about a couple of websites that allow you to create STL models of Earth’s surface: Terrain2STL and TouchTerrain. I recently discovered another website that allows you to create 3D models of both terrain and streets: Map2Model.

While Terrain2STL and TouchTerrain focus on generating 3D models of terrain, Map2Model is focused on generating 3D models of “typical” map features such as roads, buildings, water, and other features.

Start by searching for an address or a named location, then zoom in/out and center the map where you’d like to generate your 3D model. Choose a shape for your model: rectangle, square, circle, etc. Then position and size your shape on the map and press the “3D Preview” button to view, zoom, and rotate your 3D model. If happy with your model, export it in either 3MF or STL format.

For roads, water, grass, buildings, sand, and piers, there are settings that allow you to modify colors, model height, and other options which are useful if exporting in 3MF (but will not be represented in STL files because those file represent only geometry data). There are experimental features such as adding topography (similar to the terrain-focused 3D modeling websites) which in my experience with a few locations works pretty well.

Resultant models can be used for personal use, but for commercial use you’ll need to obtain a commercial license. Many thanks to Smoggy3D for developing such a nifty application!

3D Model Repositories

If you’re a 3D printing hobbyist like me, you might enjoy downloading and printing 3D models that other people have painstakingly created. Whether your 3D prints have practical applications (e.g., containers, GoPro mounts, phone holders), are used for decorative display (e.g., art sculptures, HueForge prints, figurines), provide entertainment (e.g., games, puzzles), or other reasons, there is a chance that somebody has created a model that meets your criteria. There are many repositories where 3D models can be sold or even downloaded for free. Here are my 3 favorite model repositories.

Thingiverse is one of the early pioneers of open source 3D models and is one of my favorite repositories. It has a long history and is currently owned by a 3D printer manufacturer called Ultimaker. Ultimaker is also the developer of an open source slicer called Cura, and while Thingiverse features an “Open in Cura” button in its model download page, that is currently the full extent of its workflow integration with a slicer. However, I like Thingiverse because it features one of the largest libraries of 3D models around, and everything that you see on Thingiverse can be downloaded for free. Designers who upload 3D models to Thingiverse can connect their accounts to one of several donation platforms (PayPal, Ko-fi, Github, Patreon, or BuyMeACoffee) to accept tips, but beyond a relatively inconspicuous “Tip designer” button on each 3D model’s page, the central focus of Thingiverse is around sharing open source models rather than commerce.

MakerWorld is a newer 3d model repository that is owned by 3D printer manufacturer Bambu Lab. MakerWorld is another one of my favorite repositories because it has a very active designer community that uploads an extensive assortment of 3D models. All models in MakerWorld are free, and there is an unobtrusive incentive system for designers to earn points that can be redeemed for Bambu Lab merchandise. It features workflow integration with Bambu Labs’ default slicer, Bambu Studio, in the form of print profiles. Any 3D model may be linked with 1 or more print profiles which includes slicer settings such as layer height, wall loops, infill density, or other slicer settings that are uploaded by the original designer or other users who have downloaded and successfully printed the same 3D model. Simply clicking on a print profile on the MakerWorld website results in launching and loading the model into Bambu Studio, along with the relevant slicer settings in the chosen print profile. Despite this tight integration with the Bambu Lab ecosystem, models can be downloaded and sliced in other slicers and printed with 3D printers other than Bambu Lab.

Printables is owned by Prusa Research, the same company that manufactures open source Prusa 3D printers and develops PrusaSlicer. Most models in Printables are free, although Printables features a separate Store where designers can sell their models as well. I appreciate how the free models are shown by default, and a user must navigate to the Store section of the website to browse and purchase models that are sold for a fee. There is a reward system where designers and visitors can collect points in exchange for filament or other rewards. Models can be downloaded or opened in PrusaSlicer, although there do not appear to be any print profiles that accompany the model files.

In addition to my 3 favorite model repositories above, there are some honorable mentions that I’ll briefly discuss.

Creality Cloud is owned by—you guessed it—Creality. There are free and paid models mixed together, and there is print profile integration with Creality 3D printers. This appears to be a recent development, but I have not been able to test it because I no longer have a Creality printer. Much of the user experience centers around 3D model sales, so I generally don’t visit this repository regularly.

Cults 3D is an independent, self-financed site that is run by 4 guys in France who state in their “About” page that their advantage is they they not accountable to any investor or brand. Although there are both paid and free models, one thing I like about their search function is that the results page can be filtered to show only free models.

Thangs is registered to Physna, a company that advertises itself as providing the the world’s leading geometric search engine. It contains a lot of free models, and also has a marketplace for buying and selling models.

Are there other 3D model repositories that you like to use often? Feel free to leave a comment and describe your favorite 3D model repository.

Simplifying 3D Models

Have you ever used an application to generate a 3D model and ended up with an enormous .stl file? When I use HueForge, the resultant .stl files are usually around 125 MB. When I use TouchTerrain, I also end up with large 3D models. However, unnecessarily large models require more time for slicing and more storage space. Furthermore, if you plan to share your models on Thingiverse or other 3D model repositories, it may not be necessary to propagate such large models. Finally, what’s most important to me is that sometimes I want to edit models in Tinkercad, but 3D model imports are limited to files with 300,000 triangles or less. This is where mesh simplification comes in handy.

Mesh simplification, also known as mesh decimation or polygon reduction, is the process of reducing the number of polygons in a 3D model while maintaining as much of the original shape, appearance, and important features of the model as possible. This is similar in concept to compressing images and audio files where the intent is to reduce file size while preserving as much of the image or audio quality as possible. Mesh simplification is a feature of Blender, Meshmixer, MeshLab, SolidWorks, and other 3D modeling applications. But what if you don’t have any of these applications? While some of them are free to use, I haven’t wanted to install an application for the sole purpose of using its mesh simplification feature.

Fortunately I discovered 2 potential solutions that are both free and can run straight from your web browser. The first is 3DLess.com where you simply choose your file, specify the target number of vertices, and save your file. If you are concerned about privacy, a big benefit is that the processing happens locally on your web browser, meaning that your file is not uploaded. In my limited experience, this has not successfully reduced polygon counts or file sizes on the large .stl files that I’ve been trying to simplify. I assume I’m doing something wrong, so I mention this website in case others find success with it.

My preferred option is Fast Quadric Mesh Simplification. Simply choose your file, specify a % reduction, and click the “Simplify” button. I’ve found that it simplifies 125 MB HueForge files in a matter of seconds, and despite reducing polygons to 10% of its original size, I cannot visually tell the difference between the original and simplified models. Most importantly, this website has reduced models to the point where I can import them into Tinkercad and make simple modifications.

If you are looking for a free and easy solution to simplify your 3D models, I hope you are able to get great results with one of the above options. If you are aware other other websites that do something similar, let me know!

3D Modeling Earth’s Surface

Have you ever wanted to create a 3D model of a specific section of earth’s surface? I heard that it could be done using topographic data from the U.S. Geological Survey (USGS). So I asked ChatGPT to tell me step by step how to convert USGS topographic data into a 3D model in .stl format (see thread here). In response, ChatGPT told me that I need to:

1. Download USGS topographic data
2. Preprocess the data using GDAL to convert to ASCII Grid
3. Convert ASCII Grid to a 3D mesh using QGIS and the DEMto3D plugin
4. Optionally refine the 3D model in MeshLab
5. Save the final model in STL format

That sounded complex to me, as it involves applications and file formats that I have not previously worked with. Fortunately, I discovered that there is a much easier and faster way to get 3D models in .stl format. Simply use a website that provides this specific service. Here are 2 options:

Terrain2STL is a website that allows you to create .stl models of the surface of Earth. Its interface is pretty straightforward. You can zoom/drag to a location using Google Maps which defaults to Terrain View. You can also enter GPS coordinates (refer to this post for a refresher). Next, enter details about the width, height, and other details related to the dimensions of your desired model. Then adjust settings related to water and base height and finally export your model in .stl format. Terrain2STL has the advantage of its simplicity, but its main disadvantage is its resolution which is limited to 90 meters. Here is a screenshot of Terrain2STL (click to enlarge):

TouchTerrain is another website that allows you to create 3D printable terrain models. Similar to Terrain2STL, TouchTerrain allows you to zoom/drag to a location using Google Maps, but TouchTerrain also allows you to search for a place by its name, address, or GPS coordinates which can be very useful. TouchTerrain also allows you to choose from 3 different elevation data sources, each of which has varying resolution ranging from 10 to 2000 meters, depending on its purpose. For me the default USGS data source with 10 meter resolution produced a model with the level of detail that I was looking for. It also has inputs for 3D printer settings such as your build plate dimensions to help you determine the maximum size of your model. After inputting the relevant settings, generate and download your .stl model. Here is a screenshot of TouchTerrain (click to enlarge):

After you get your desired model from either Terrain2STL, TouchTerrain, or another method, you’ll be ready to slice and 3D print your model.