OpenCSG 1.8.1

OpenCSG is a library that does image-based CSG rendering using OpenGL. CSG is short for "constructive solid geometry" and represents a modeling technique for composing shapes with 3D-primitives which are combined using volumetric boolean operations. Image-based CSG rendering means rendering CSG shapes without calculating their surface in object-space. Instead, the image of a CSG shape is composed directly in the frame-buffer of the graphics hardware by rather sophisticated stenciling and z-buffer operations.

Tags c++ graphics opengl cad 3d-rendering
License GNU GPL
State mature

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Recent Releases

1.8.109 Mar 2025 14:06 minor bugfix: This is a bugfix release. Most importantly, it makes the recently added GLSL vertex shader call also work with OpenGL versions 2.0 and 2.1. Before, an internal fragment shader had an OpenGL 3.0 requirement, and so rendering failed with older OpenGL versions.
1.8.002 Mar 2025 20:46 major feature: The new release contains a number of changes to avoid z-artifacts. Most importantly, it is now possible to provide a GLSL vertex shader to OpenCSG. If a compatible shader is also used in the calling application to process the geometry, this can avoid z-artifacts that happened with older versions. The new release also provides minor performance improvements in the SCS algorithm, by reducing the number of rendered primitives using shorter permutation embedding sequences. And for building on non-Windows platforms, it has switched from the old qmake-based makefiles to CMake.
1.7.018 Jan 2025 16:09 minor feature: Rendering improvements for the case that the camera is in the interior of the CSG object. With previous releases, this case resulted in rendering errors. Now, this case is, depending on parametrization, handled correctly.
1.6.015 Sep 2023 19:30 cleanup: On Linux, the implicit dependency on GLX has been removed. So OpenCSG can be used on systems now that come with EGL.
1.5.120 Apr 2022 15:18 cleanup: Fix for a compilation error introduced with the previous version 1.5.0, that particularly occured with recent gcc versions.
1.5.010 Apr 2022 17:40 cleanup: With OpenCSG 1.5.0, the license is changed from GPL version 2 only to GPL version 2 or newer. The release also contains small API cleanups.
1.4.229 Sep 2016 06:42 minor bugfix: Release 1.4.2 fixes a bug if the calling application renders into OpenGL frame buffer objects. In particular, using OpenCSG from a Qt5 QOpenGLWidget is more reliable now.
1.4.111 Sep 2016 09:58 major bugfix: Release 1.4.1 fixes rendering of CSG expressions with the SCS algorithm on Intel graphics hardware.
1.4.017 Sep 2014 20:42 major bugfix: The new release 1.4.0 contains bug fixes for rendering CSG expressions made up from more than 255 primitives. OpenCSG implements a couple of different algorithms for rendering CSG, and all of them now work correctly for geometry that exceeds this number of primitives.