From 2D concept to print-ready miniature
Board game miniaturist Justin Bintz shares his tricks of the trade, walking though the creation of one of the many minis created for a 3dtotal Games project
Justin Bintz talks to us about how he developed 2D concept art into a ZBrush miniature, ready for the printers. He transformed Sean Andrew Murray's design into a 3D games model using ZBrush for our Wizard's Academy board game.
Ideas for 3D printing
When tackling a 3D model for print, it is essential is to always keep a few key ideas in mind. Namely, you want to remember to: (a) keep the model simple, (b) keep your details large and exaggerated, and (c) always be mindful of the thickness of any piece you build. If you work with these details in mind, you will save yourself hours of revisions and have a much more successful miniature in the end. We'll use Nyvetta, the first character I made for 3dtotal, as an example project.
Working with large detail
When I model any piece, I start off with a sphere and use SnakeHook to quickly block out the silhouette. While blocking out I tend to think about the weight of the character and how it will fall, making sure to build up enough mass in the proper areas in order to allow the character to stand upright when 3D printed.
The XMD_Glob brush is fantastic to build up mass in a smooth and gradual manner. Once the character is massed out, I find using the TrimDynamic and the Dam_Standard brushes really help to define the edges and planes on my models. These hard edges prevent the loss of detail once the model is 3D printed at only a few inches tall.
This particular model required fur, a challenge for 3D printing because of the small size and repetitive nature of it. Using the XMD_Glob brush with the Dam_Standard brush gives a great effect while still keeping the detail nice and large.
So once you've modeled all your larger details and are working on smaller, more concise areas, you need to ask yourself a couple of questions. Should I bother with stitching? Should I add in skin pores or other micro details? To answer these questions I like to shrink my model on the screen to whatever size it will be once printed; it's a quick, efficient way to see how much of your hard work is actually going to show up.
Once your model is finished and you're happy with the level of detail your miniature will display, we leave the artistic side of things and begin to tackle the 3D printing process head on. In the following steps I'll show you exactly how I prepare a model for 3D print. It's an often daunting task that I am hoping to be able to simplify below.
When preparing a finished model for 3D print the first step is eliminating gaps. You want pieces to overlap heavily. Making items feel sturdy at this point is crucial.
I'll demonstrate one way I eliminate gaps on a shoulder pad with our example of Nyvetta. Here, image (A) shows that the shoulder pad is slightly hovering above his robes. This piece would be incredibly flimsy after it's printed and could be destroyed all together.
To remedy this, we take the Move Topological brush and turn on BackfaceMask. We then grab the edges of the shoulder pad and drag to the sleeve. The brush won't take the top half of the shoulder pad because we have BackfaceMask turned on. This method takes some playing around with and heavily depends on your camera angle, so take your time and experiment.
3D Printing companies have different rules about what you can deliver them. I've found the most success by delivering one big mesh that contains an air tight wall. DynaMesh is a fantastic way to prepare your models for 3D print. It makes the process of preparing models for 3D print, with any service, much simpler.
First you'll want to merge all of your SubTools together, there are multiple ways to do this and any way you achieve this is fine. Once your model is in one SubTool, you can find the DynaMesh tool under the Geometry menu. I highly recommend saving your file before attempting to DynaMesh your model. Attempting to DynaMesh at a high resolution can easily cause ZBrush to crash.
I typically start at a lower resolution and, if the detail is murky, I will Ctrl+Z and move the resolution slider further and then DynaMesh again. I repeat this until I'm happy with the detail DynaMesh has given me. Once we are happy with the detail level, we have a single, air tight polygon. In just a few more steps we'll have a model any 3D service can print easily.
Reducing the polycount
The mesh is now one big piece, but it's a complex piece. The resulting mesh from Step 5 for Nyvetta is 2.6 million polygons. This number isn't a lot for us ZBrush users, but for a 3D printer this can freeze their programs easily. We'll utilize the Decimation Master, a plugin that comes with newer versions of ZBrush, to make this model easier to handle.
Simply select your model and leave the percentage of decimation at 20% and press Pre-process Current. Once the algorithm runs press Decimate Current. This will also take a minute or two to complete. Once done, we see that our mesh is much simpler. Nyvetta's polycount dropped to 520,000 just under 20 percent of the original DynaMeshed model.
If your model is still a very high polycount, simply reduce the polycount again with the Decimation Master. Playing with the percentage of decimation will give you varying results. As a general rule of thumb: the higher the percentage of decimation, the less your model will reduce in polycount.
At this point we're ready to leave ZBrush with our miniature. This process is actually quite simple. To get our STL file, we use yet another plug-in that comes standard in new versions of ZBrush, called 3D Print Exporter. Have your now decimated SubTool selected and choose either Inch or Millimeter in the menu. The decision between inch and millimeter is a personal preference and only affects the model's size once printed.
Once you have the desired measurement selected, click Update Size Ratios. This locks the X, Y, and Z numbers proportionally to each other based on your model's width, height and depth. Because size is ambiguous in ZBrush, we're able to choose any size for 3D printing without an issue. Move the Y Axis number to your desired height and simply hit the STL button, choose where you want your file to be saved and we're all done in ZBrush.\
Now we begin using a free program called Netfabb. Netfabb is a stand-alone piece of software for 3D printing. It offers a wide variety of tools to help prepare our models for the printing process. I specifically use the software to quickly fix a plethora of small issues in my 3D models that are about to be sent off to printing services.
Once Netfabb is booted up, select the Part menu and then click the Add button. Select the file path of your exported STL file and we're up and running. Now we go to the Extras menu and select Repair Part. This will quickly process your model and pop up a new, docked menu on the right.
Once this new menu appears, click Automatic Repair on. When a small new menu pops up, select Default Repair and press Execute. The repair will process for a minute. Once it's completed, simply press Apply Repair and accept by pressing Yes to the new window that pops up. Again the program will process the model quickly. At this point you've eliminated flipped triangles, stitched triangles, double triangles, and you've successfully closed any trivial holes in the mesh that you had no idea existed.
Exporting the STL file
One more step needs to be completed inside of Netfabb and it's actually during the exportation of our final, ready-to-print STL file. In the Part Menu select Export. Select a destination for your new STL file to be saved and click Save.
After you select your file's destination, a new export menu will pop up. It has a final repair available to you for your 3D models… and this one is crucial. A 3D model with Manifold edges may not print properly and Netfabb lets us know exactly how many there are and has a one-click fix. Essentially, manifold geometry is geometry sitting directly on top of another piece. Visually it's the same as if you extrude a piece of geometry in Maya, but don't move your extrusion anywhere.
Click Repair and Netfabb will take care of the rest. Your file is now absolutely ready to be 3D printed by basically any service available to you online!
Top Tip: Keep it simple
When building characters, all ZBrush artists love getting down to the micro detail, peppering on alphas to bring models to life and adding in all sorts of complex damage. As an artist creating miniatures, you need to keep in mind the scale of your final piece.
You should exaggerate aspects of your character so someone playing the game can easily identify what type of character it is. Don't make gamers have to get a magnifying lens to see that what is in front of them is in fact a dwarf warrior and not a mass of plastic. Have fun with your creation and the players will have fun seeing your work!
Visit Justin's website for more of his models and miniatures
Inspired by Sean Andrew Murray's fantastic artwork? Check out more of his work here
If you want to learn some new ZBrush skills or ‘brush' up on old ones then take a look at our training eBooks
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