mbitsnbites / solidaritycsg

A library for quick and robust constructive solid geometry (CSG) operations on triangle meshes

⚠️ This repository has moved to: https://gitlab.com/mbitsnbites/solidaritycsg

SolidarityCSG

SolidarityCSG is a library for quick and robust constructive solid geometry (CSG) operations.

As input and output, the library supports triangle geometries (meshes), and internally the library uses a voxelized representation of the volumes.

Building

Use CMake to build the library, tools and docs:

mkdir out && cd out
cmake -G Ninja ..
ninja
ninja doc

Using the library

The SolidarityCSG library can be used by applications to perform CSG. See the Doxygen documentation for more details.

Using the csg tool

A small demonstration tool that uses the SolidarityCSG can be found in the tools directory. After building, it can be found in out/tools/csg.

The csg tool takes one or more scene description XML files as input:

$ tools/csg myscene.xml

Example scene XML file

<?xml version="1.0" encoding='UTF-8'?>
<csg>
  <settings>
    <resolution x="0.01" y="0.01" z="0.01" />
    <output name="example" type="mesh" format="stl" />
  </settings>
  <volume>
    <difference>
      <box cx="0.0" cy="0.0" cz="0.0" sx="1.0" sy="1.0" sz="1.0" />
      <mesh src="3d-models/bunny.stl" />
    </difference>
  </volume>
</csg>

About the resolution

Be careful when selecting the resolution. Since the entire scene is sampled and reproduced at the given resoltuion, a too fine resolution will lead to high memory usage and very large output files. On the other hand, a to coarse resolution will lead to a poor result.

Example outputs

• 3D model in STL format:
  • <output name="example" type="mesh" format="stl" />
• 2D slices (many TGA files):
  • <output name="example" type="slice" format="tga" />

Valid CSG operations

There are three supported CSG operations:

• <union>
• <difference>
• <intersection>

Valid shapes

There are three supported shape types: two mathematical shapes (sphere and box) and one triangle mesh shape (mesh):

• <sphere cx="0.0" cy="0.0" cz="0.0" r="0.6" />
• <box cx="0.0" cy="0.0" cz="0.0" sx="1.0" sy="1.0" sz="1.0" />
• <mesh src="3d-models/bunny.stl" />

License

The library is released uneder the GNU LESSER GENERAL PUBLIC LICENSE. See COPYING.LESSER and COPYING for more information.