greenxenith / meshport

Easily export areas in Minetest to meshes for 3D rendering.

Meshport (Minetest Mesh Exporter)

Meshport is a mod which allows easy exporting of scenes from Minetest to .obj files, complete with materials and textures. These models can be imported directly into Blender or another 3D program for rendering and animation.

This mod is still in the "alpha" phase; as such, many types of nodes are not yet able to be exported. See below for more details.

Usage

Use /mesh1 and /mesh2 to set the corners of the area you want exported, then use /meshport [filename] to export the mesh (filename is optional). The saved .obj and .mtl files will be located in the meshport folder of the world directory, within a subfolder.

Importing into Blender

Once the model is exported, you should be able to import the .obj file with default settings. Make sure "Image Search" in the import settings is selected to ensure the textures are imported as well. Texture modifiers are ignored, so some materials will likely have to be fixed by hand.

Fixing materials

Blender's packaged material assigned to OBJ textures are not effective or easy to use. By default, textures will also appear blurry and lack alpha. The materials.py script is included in the mod to simplify the materials, change interpolation, and add transparency. Open the script in Blender's text editor and run the script with the mesh selected.

Fixing vertex normals

Some mesh nodes may not have any vertex normals, which can lead to lighing problems. To fix this, what I have found to work is to first select the all the problematic nodes, either manually or by selecting by material in edit mode; then, mark the selected edges as sharp, and then average the normals by face area.

Additional tip: Use an HDRI sky texture (such as one from here) for awesome-looking renders. ;)

Supported features

At the moment, only the following node drawtypes are supported:

• Cubic drawtypes, including normal, glasslike, allfaces, and their variants (see below)
• nodebox
• mesh (only .obj meshes are exported)

Many special rendering features are not yet supported.

A note on cubic nodes

Due to the differences between Minetest's rendering engine and 3D programs such as Blender, it is not possible to exactly replicate how certain cubic nodes are rendered in Minetest. Instead, to avoid duplicate faces, a face priority system is used as follows:

Priority level	Drawtypes
4	normal
3	glasslike
2	glasslike_framed and glasslike_framed_optional
1	allfaces and allfaces_optional
0	All other nodes

In places where two nodes of different drawtypes touch, only the face of the node with the higher priority drawtype will be drawn. For allfaces type nodes (such as leaves), interior faces will be drawn only when facing X+, Y+, or Z+ in the Minetest coordinate space.

License

All code is licensed under the GNU LGPL v3.0.