Mineways

With the free Mineways program you can interactively select a model from a Minecraft world map and have a 3D printing service make a real model for you. Or send it to your own 3D printer, or just enjoy rendering it. Some results, so far, all in the $10 to $65 price range from Shapeways - click on an image to see the full series:

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Let me know of any bugs you find and features you'd like. The program is open-source and is based on the (great) open-source program minutor written by Sean Kasun - his work gave me a huge headstart. Mineways is a superset of his mapper, with a model exporter and other features added. I wrote this program just for fun, I'm not associated with Shapeways or Mojang. There are other print services that work with Mineways, such as i.materialise and Ponoko, as well as home 3D printers, such as RepRaps and Thing-O-Matics (wiki).

L'Effie Tower. From left to right the images are: in Minecraft, selected in Mineways, previewed with the SAP Viewer Complete, delivered from Shapeways. Click on an image to enlarge it, here to download the model, here for a brief video clip of the result, here for more photos of the real thing, and here to order from Shapeways (though, really, you should just make your own models!).

Super-fast quickstart: Download and unzip (using 7-Zip or other decompressor) to some directory, like the desktop. Double-click mineways.exe to run. Use "File | Open World" to select a world. Use the left mouse button to drag the map around, use the mousewheel to zoom. Use the right mouse button to select an area on the map and to adjust this rectangle. Optionally use the middle mouse button to select a depth. Export the model for rendering or 3D printing - just hit "OK" when presented all those options.

You can import OBJ (.obj) model files into Blender or other rendering packages. You can preview VRML (.wrl) 3D print files fairly well using the free SAP Visual Enterprise Viewer Complete - install and then double-click the .wrl file. Once you like the print file, zip both the .wrl and .png files, then upload to Shapeways.

We'll run through each of these steps in detail. If you don't want to wade through it all, at least search on the phrase "Key tip", as these bits are particularly useful.

Installation

Installation is trivial, and there not much to add to: Download and unzip (using 7-Zip or other decompressor) to some directory, like the desktop. Double-click mineways.exe to run.

Uninstall: just delete the directory. If you created color schemes, there will be a few small entries in the registry: if you really want to clean it all, search for "Mineways" and you'll find them.

Mapping

Basic map use:

Color Schemes

Color schemes allows you to change the color for any block, and to also eliminate any blocks you want from view (e.g., remove grass, dirt, stone, sand, clay, and gravel and you'll see a lot of ore deposits). Add a new color scheme, then Edit it. Change the name "Color Scheme" at the top of the dialog that pops up, then select any block type to edit it. Color is given in hexadecimal color format. You can use MWSnap (old but free), FastStone Capture (new but costs $20), or other programs to find the hexadecimal (e.g. #787878) color value of any pixel on your screen. 'Alpha' says how opaque a block will appear on the screen, with 255 meaning fully opaque and 0 meaning fully transparent (invisible). Blocks with an alpha of 0 will be deleted when exporting. You can turn off export of all blocks by using the "Hide All Blocks" button. This feature allows you to create separate parts, e.g. a glass roof could be created by then turning on just glass export.

Shortcut keys

Most operations can be done with the mouse: left button and mousewheel for viewing, middle mouse button for setting the depth to whatever is at that location, right mouse selects a region to export - more on this in the Selection section.

Selecting a Region

To create a 3D file for viewing or printing you first select a 3D box in your world. Whatever is in this box is exported. Hold down the right mouse button and drag to define a selection area. Key tip: once a region is defined, you can use the right mouse button to select an edge or corner and drag to fine-tune the rectangle.

By default the heights used for the rectangular block are y=62 (sea level) to y=127. The altitude slider at the top of the window determines the maximum height, but usually you'll leave this one alone. You'll use it for selecting areas fully underground or in the Nether. The number keys 0-9 can be used to quickly shift the maximum height; the < and > keys shift the altitude by one.

The current lower depth of the selected volume is shown in the status window at the bottom of the screen as "Bottom". You can change this lower depth at any time, regardless of whether a volume has been selected. The lower depth can be changed in a number of ways. If you click the middle mouse button over a location, the lower depth is set to the height of that location. The [ and ] keys shift the lower depth by one, and so are invaluable for tuning.

Example: at first, the selected area does not include the terrain below. By clicking on terrain with the middle mouse button, the level is lowered. Clicking again on the unselected area, the lower depth is now set low enough to capture all terrain. Bright pink shows terrain exactly at the lower depth.

In the image on the left an area is selected but the lower depth is too high, so parts of the terrain are not selected. Adjusting the depth downwards selects this terrain.

Key tip: to see what you're doing, export the model and view with the SAP Viewer Complete or other tool. I usually work by adjusting the box size and export options in Mineways, export, then reload the file in the SAP viewer to see the results.

Exporting Models

Select "Export Model for Rendering" from the File menu, or use control-R, and save your file. The resulting file(s) can then be imported into a huge variety of 3D modelers and viewers, e.g. Blender. Alternately, you can select "Export Model for 3D Printing", control-P, to create a model suitable for sending to a 3D printer.

The big difference between rendering and printing is that 3D print models must be solid and well-formed. Currently Mineways treats all blocks as solid, full blocks: half-steps or stairs are treated as blocks, as is every other block. There is also no transparency for the materials, since printers do not currently support this type of creation. Models for rendering can, when full texturing is on, include billboard models for flowers, saplings, crops, and other elements. Note that the billboard locations are added in comments to the output .OBJ and .WRL files. In this way, a dedicated modeler could substitute his own elaborate grass, flower, or other models in place of the simple billboards Minecraft provides.

"My Model's Too Expensive!"

If you export to print and upload to Shapeways, you might be surprised to find that the price is sometimes just shy of a used car. For example, this model of our spawn area is 15 x 9.8 inches in size (about 190 x 125 blocks, 2 mm wide), and costs $633.14. Expensive models happen because either the model is too small, or too large. The problem with small models is that each block itself is massive. If you scale a small model to a large height, the blocks themselves become larger and you have to pay for each block's volume. Mineways can't help you much there, you'll need to use a CAD program to hollow out your object manually. Shapeways has a tutorial on hollowing.

The other problem you may run up against is the blocks are not small enough. This happens with larger models, those 100+ hour darlings you sweated over in Minecraft. The cause is that, by default, Mineways exports the model to print at a safe size. Colored sandstone has a thin wall dimension of 2 millimeters. This means if some wall in your model is less than 2 mm thick, it is in danger of breaking into pieces if printed in color. There are some solutions to the price problem:

By the way, I hear "it would be cheaper using LEGOs" a fair bit. LEGO blocks cost around 4-5 cents a block, 2 mm colored sandstone 3D printed blocks run about 6/10th of a cent. There are advantages to LEGOs (larger, reusable, fun to make) and disadvantages (no textures, not perfect cubes), but LEGO cost is not an advantage.

Model check: the SAP Viewer Complete has a wonderful feature: cross sectioning. You can slide a plane through your model and see the interior spaces. This can help you determine where to place your box for printing, how well hollowing is working, where to build escape holes, etc. On the flip side, this viewer has a defect in its display of tree foliage when viewing render (but not 3D print) exports: from some angles you see through all the foliage. This is from it not setting alpha testing properly; use G3D instead if you want to preview for rendering (it also loads faster).

SAP Viewer Complete: on the top, the wonderful cross-section viewer in action. Below, leaves look fine in the left view; on the right, leaf cutout problems.

By default, Wavefront OBJ *.obj (and *.mtl) files are exported for rendering, VRML97 (aka VRML2) for 3D printing. Here's the rundown of the various file types you can select, including some subtleties about each.

OBJ: Wavefront OBJ is an old format, so is commonly supported as an import format for a huge range of applications, including the free Blender package. If you export materials, a corresponding *.mtl file is output; if you export textures, a *.png is also created. The .obj and .mtl files are text files, so can be easily edited or processed further. Currently Shapeways does not read in color OBJ files, so any OBJ files zipped and uploaded will print only in a solid material. Use VRML97 to export color files for 3D printing.

OBJ, no material preview: A subtlety of OBJ is whether the material file should influence the texture file. Some viewers, like the SAP Viewer Complete, will multiply the texture by the material. By selecting "no material preview" for the OBJ file, a minimal material file is generated.

Binary STL: This file format is commonly used by 3D printers. It normally is used for single-color materials, but the exporter will used either the Materialise Magics or VisCAM format to attach colors to triangles - see this article. When STL files, binary or ASCII text, are exported a corresponding *.txt file is generated with information about the model. This same data is included in the beginning of the *.obj and *.wrl files themselves.

ASCII text STL: A variant for 3D printers, the file generated is considerably larger than the binary form and cannot include color. The main advantage is that this file type is a simple text file and so can be easily edited. The format is trivial and so can provide a raw set of triangles for a model.

VRML97: Also known as VRML2 or VRML 2.0. While this format has been superceded by X3D, it is commonly supported by a wide range of packages. That said, its main reason for existence here is that it's the one file format that Shapeways uses for colored models. The *.wrl and *.png file created are put into a zip file and uploaded to Shapeways for printing - see more about this process below. The VRML file produced is tailored towards making a single texture for printing. When previewing, this is the best format to use with the free SAP Viewer Complete.

Rendering Tips

This section covers the basics on importing Mineways files into various renderers. I know little about particular renderers, so rely on you guys out there to inform me. I'd love information on 3DS MAX, Maya, Blender, Octane, etc. That said, if you want better geometry and other features, you should try out mc2obj; Mineways' focus is on 3D printing more than rendering. While I have your ear, you should also check out OptiFine for in-game play: it has lots of cool rendering options.

Previewing: to quickly check results before importing into a rendering program, consider using an interactive previewer. The SAP Viewer Complete is a good previewer for 3D print models, but not so fantastic for viewing models made for rendering. I recommend the G3D viewer when using full color textures. It does not have cross-sectioning and supports only OBJ files, but has much better transparency support and shadows, loads much faster, and has screenshot and video capture built in (note: the viewer32.exe is the one that supports video capture). Unzip and double-click the register.bat file to associate it with OBJ files (or just do this manually, if you prefer). Here's an example, side to side, of this set of sampler files, which show one of (almost) every block in Minecraft.

On the left, SAP Viewer Complete showing the VRML (WRL) printing file; on the right, G3D on the OBJ rendering file:

Cinema 4D

Here are steps from James Christien (icecruiser xD; example C4D result here), with help from Huskiee on alpha.

Step 1: Get your world and region selected in Mineways, then select 'Export Model for 3D Rendering'.

Step 2: Save as the file type 'VRML'.

Step 3: Adjust your option accordingly:
- Tick the 'Export full color texture patterns' button.
- Make the model 1000 CM in height so it's not super tiny in Cinema4D (optional)
Do everything else to your liking.

Step 4: Once the model is exported, open Cinema4D and drag into the main window the 2 files (.png and .wrl) generated.

Step 5: Once it is all loaded, if black ugly things are present on tiles - such as grass or torches - then double-click the material in the materials viewer. The materials viewer is the round sphere with materials on it, at the bottom of the interface.

Step 6: On the material options, on the left side options bar, check the Alpha option and go into its preferences window by clicking it after you checked it.

Step 7: In the alpha settings, come down to the Texture setting and click on the little arrow on the right, go down the menu and select Bitmaps, and choose the material name (there should only be one) in the small window that pops up after clicking Bitmaps.

Step 8: All the black things should be gone, ready to be used and rendered properly.

Export options

There is a bewildering dialog that pops up on export, with a ton of options. You can blithely ignore this option and always just click OK (or the Enter key). However, some of the options are extremely useful, so plow on if you want to make sure your model is strong enough and still cheap as can be.

World coordinates selection: you can see and change the 3D volume of space to export from your world. Key tip: You can view the output *.obj or *.wrl with a text editor, like Notepad (or, better yet, Notepad++). By doing so, you'll see a line like this: 

# Selection location: -80, 72, 66 to -66, 127, 104
By putting these numbers in the 6 coordinate boxes, you can easily continue to work on a model between Mineways sessions. If you want to know the location of a place in your world, use the F3 key when playing Minecraft. Note that negative values like -5.239 will round down to -6, and also note that your Y-value altitude is one higher than where your feet are located, and so two higher than the ground beneath you.

Create a ZIP: like it says, on export a ZIP file of the exported files is created, ready for upload for 3d printing at Shapeways or other service. Note that the exported files themselves are also still immediately available for previewing.

Material export: these are pretty much as they say. The "no materials" option is just that. "Solid material colors" will give solid swatches of color for each material. "Richer color textures" gives texture tiles that have some noise in them. For the OBJ file format the difference is that a PNG texture file is output; VRML97 always exports a texture for any material option. "Full color textures patterns" requires the terrain.png file (look at the start of this page for more info), reading this file to create full textures for each block, as possible. Some blocks, such as fire, do not have any texture in the terrain.png image, so are rendered as solid blocks. Remember that for any format you can always turn off a block from being output by setting its alpha to zero in your own color scheme. For "full textures" the color scheme has no other effect, other than affecting the water color: the higher the alpha set, the more of the base color you define is combined with the water texture. So, for a deeper blue, you can define the two water colors (note there's a "stationary water") as dark blue or even black and a high alpha, e.g. 200.

The one file you may want to change is the terrain.png file that comes with Mineways, which is from the Ancient Roots texture pack. Minecraft itself and all texture packs make their own terrain.png files. If you unzip a texture pack, you'll see the terrain.png inside. To select a different terrain.png file, use the "Select terrain.png for export" under the File menu. If you have a terrain.png file you would always like to use by default, copy it into the directory where mineways.exe is located, replacing the one that is there.

Note to terrain.png experts: I do use the four tiles in the rightmost column, at the bottom, for water and lava (water, stationary water, lava, stationary lava). One warning: 128x128 and larger tile texture packs will work (and will take awhile to process), but previewing these files in an interactive viewer like the SAP Viewer Complete may not work. This is because DirectX and OpenGL has limitations on the maximum texture size. These texture files should display fine in offline renderers.

The tiles are each given a border 1 pixel wide. This border avoids bilinear interpolation artifacts. However, mipmapping will not work well, since tiles are next to each other, so disable it for rendering (other sampling techniques should work fine). If you cannot disable bilinear interpolation in your renderer and want a more blocky look, take your terrain.png file and resize it to be say 4x larger in both directions; alternately, resize the texture(s) that Mineways exports. Make sure you just use a "pixel resize" without any filtering, e.g. in IrfanView use "Resize (faster)". Download this example and put this one in place of the terrain.png in your Mineways program directory to see the difference. This higher resolution may improve the clarity of 3D texture printing - we're not sure at this point.

On the left, the basic 256x256 terrain.png file is used; on the right, the input terrain.png image is resized (without filtering) to 1024x1024.

Make Z the up direction instead of Y: some graphics applications consider the Y direction to be "up", some Z. If your model imports sideways into your application, check (or uncheck) this box.

Center model: when checked, the center of the bottom of the model is put at the origin, location (0,0,0). This helps for import into a renderer, and can improve the floating-point resolution of the data. If you want to instead have the same coordinate values as in your world, uncheck this box.

Export all block types: by default smaller objects, such as flowers, signs, etc., are culled out when exporting solid materials - only nearly-block-sized or important blocks are exported. This option is on by default when exporting full color textures for rendering; turn it off to remove the "billboard" objects. Remember you can also turn off output of any block type by setting its alpha to zero in your own custom color scheme.

Merge flat blocks with neighbors: some blocks, like redstone wire, repeaters, snow, ladders, wall signs, etc., can be glued onto neighboring blocks, changing their faces. By default we do this; turning this option off (why?!) will generate full blocks for these objects. I haven't done much work on this option, as I never turn it off.

The rest of the options mostly have to do with 3D printing, which follows.

Exporting to 3D print

As background, view the Shapeways 3D color printing process video. Layers of material are laid down and solidified at the appropriate spots. Unsolidified "sand" is vacuumed away. You pay by volume, not by complexity. What this means to you is: avoid making enclosed spaces with tiny entrances. Unfortunately, most buildings are just that: large rooms with small doors. Your job is to make sure your model has either no openings at all, in which case the Hollow option can clear out the inside, leaving just a shell. Alternately, make escape holes yourself using snow blocks, which you then melt after all processing of your model. I'll explain these options below.

There are other potential pitfalls with 3D printing, such as thin wall problems (more here), and too many polygons (rare for a Minecraft model), to name just two. Shapeways' tutorial pages and materials pages give you a lot to chew on. The Mineways program tries to guide you past the major pitfalls, but it's always possible to generate something that's essentially unprintable: too weak, holes too small to clear out the dust, etc. Browsing the tutorials there should help you understand what is possible.

Options follow.

Rotate model clockwise: this is useful when you want to display a model on Shapeways. The view of the model is rendered by Shapeways from the south-south-east. So if your model faces west, you might rotate it 270 degrees to have it face south and so display better on your models page.

Scale: There are four major ways to scale your model. For 3D printing, Mineways assumes the units are meters. If you want centimeters, as some home printers use, you currently have to multiply the values input by 100. For example, if you want to print 1 millimeter wide blocks, you have to put 100 millimeters instead. A units option will be added soon.

Physical material: choosing a material here from among the more sensible Shapeways material options sets the default wall thickness and constrains the "Aim for a cost" option. It also ensures that the price is computed for that material and output in the top of the model file (or associated *.txt file, for STL output). It's worth saying again, key tip: view the top of the output model file in a text editor for all sorts of useful information about the model and how you generated it. The "White & Flexible" material has a smaller minimum wall thickness compared to "Colored Sandstone" (0.7 mm vs. 2.0 mm), so much smaller (and cheaper) models can be created in it. White & flexible is plastic and pretty durable, colored sandstone is heavier, fairly strong, but brittle. Shapeways has a tutorial on how to paint this material, which can be fun in itself. Note that the ceramics material has a maximum wall thickness of 15 mm, something Mineways does not check; this material is also the only one where you are charged by surface area instead of volume.

Model's units: when a model is saved, the values stored are not in any particular units, like meters or inches. However, 3D printers need this scale for printing the model. Meters are assumed, as this is what Shapeways uses by default. For other services and printers, other units are assumed. Here's a brief rundown: