OpenCTM is a file format designed to store compact 3D triangular meshes. It comes with a library for developers and 3D designers to read and write OpenCTM files.
OpenCTM only handles triangular mesh data and is not a scene description format. It is adaptable to almost any application, allowing visualization systems, game engines, medical applications to customize their own scene or model description format using OpenCTM as the 3D data carrier format.
The file format (.ctm extension) has the following characteristics:
- Open format (zlib/libpng license).
- Supports storing vertex normals, UV coordinates, and custom vertex attributes.
- Can store very large geometries (billions of triangles and vertices).
- Compact storage of 3D triangulated geometries, using entropy reduction techniques, combined with advanced entropy coding (LZMA). An STL file can usually be compressed to 5-6% of its original size.
- Lossless compression with user-controllable precision:
- Lossless compression (IEEE 754 32-bit floating point).
- Fixed-point representation with user-controllable precision
The included 3D file converter (ctmconv) has the following features:
- Support for the following formats (read and write):
- OpenCTM (.ctm)
- COLLADA 1.4/1.5 (.dae)
- Stereolithography (.stl
- Stanford Triangle Format (.ply)
- 3D Studio (.3ds)*
- Wavefront geometry (.obj)*
- LightWave object (.lwo)
- Geomview object (.off)
- OpenCTM compression settings control
- Scaling and transformation
- Multiplatform: Windows, Mac OS X, Linux, OpenSolaris...
The viewer application (ctmviewer) has the following features:
- OpenGL interactive 3D view:
- GLSL-based phong shading
- Texturing
- Vertex colors
- Fast loading - perfect for previewing 3D files.
- Imports and exports files supported by the conversion tool.
- Portable (works on Windows, Mac OS X, Linux, OpenSolaris, etc.).
CAD Interop distributes several software for preparing, viewing and converting OpenCTM files. Find below the list of our solutions compatible with the OpenCTM format: