Nexus is a c++/javascript library for creation and visualization of a batched multiresolution 3D model structure.
Nexus by Visual Computing Laboratory - ISTI - CNR
Contact me @ federico.ponchio@isti.cnr.it
See INSTALL.MD for compilation instructions.
- Multiresolution
- Large models
- Textures or color per vertex
- Streaming
- Compression
- WebGL
Starting from a 3D model (.ply), drag and drop it on the nxsbuild executable, and it will be converted into a multiresolution nexus model (.nxs). Drag the multiresolution nexus model (.nxs) onto the nxscompress executable to compress it, and the result will be a compressed multiresolution nexus model (.nxz).
gargo.ply --> nxsbuild --> gargo.nxs --> nxscompress.exe --> gargo.nxz
Drag and drop either .nxs or .nxz files on nxsview to interactively inspect the generated 3D multiresolution model.
Use nxsbuild to create a multiresolution nexus model (.nxs) out of your 3D model (.ply):
$ nxsbuild gargo.ply
The result will be gargo.nxs. For large files this may take quite some time. See the man page for all the options, supported input files etc.
The model can be compressed, saving aroung 90% of the size. This is most useful for streaming applications:
$ nxcompress gargo.nxs
The result will be gargo.nxz. Detailed information about the compression parameters can be found in the man page.
Nxsedit can be used for many editing operations on the multiresolution model. For instance, you can get some statistics on the created model (bounding sphere, list of patches, etc.):
$ nxsedit gargo.nxs -i
Or also, you can simplify the .nxs file (pruning the lowest level of the multiresolution tree):
$ nxsedit gargo.nxs -l -o simplified_gargo.nxs
Detailed information about the editing parameters can be found in the man page.
Nxsview is a simple program for inspecting a .nxs file:
$ nxsview gargo.nxs
You can tune various parameters through the interface, but be sure to read the available options in the man page.
The easiest way to publish the model on the web is to use 3DHOP interface. Alternatively you can use Three.js: there is a minimal example in the HTML directory of the GitHub Nexus repository. It is strongly recommended to use compression for the models (nxscompress).
The visualization algorithm can be easily used as library inside your engine, both in C++ or in JavaScript, basically the algorithm job is to send geometry to the GPU.
All C++ Nexus software is free and released under the GPL license (it depends on Qt and VCG lib). All Javascript Nexus software is free and release under the MIT license.
Multiresolution and fast decompression for optimal web-based rendering Federico Ponchio, Matteo Dellepiane Graphical Models, Volume 88, pp. 1-11, November 2016
Fast decompression for web-based view-dependent 3D rendering Federico Ponchio, Matteo Dellepiane Web3D 2015. Proceedings of the 20th International Conference on 3D Web Technology , pp. 199-207, June 2015
Multiresolution structures for interactive visualization of very large 3D datasets Federico Ponchio Phd Thesis
Interactive Rendering of Dynamic Geometry F. Ponchio, K. Hormann IEEE Transaction on Visualization and Computer Graphics, Volume 14, Number 4, pp. 914-925, July 2008
Batched Multi Triangulation Paolo Cignoni, Fabio Ganovelli, Enrico Gobbetti, Fabio Marton, Federico Ponchio, Roberto Scopigno Proceedings IEEE Visualization, pp. 207-214, October 2005
Adaptive TetraPuzzles: Efficient Out-of-Core Construction and Visualization of Gigantic Multiresolution Polygonal Models P. Cignoni, F. Ganovelli, E. Gobbetti, F. Marton, F. Ponchio, R. Scopigno ACM Trans. on Graphics, vol. 23(3), pp. 796-803, August 2004 (Siggraph '04)
BDAM: Batched Dynamic Adaptive Meshes for High Performance Terrain Visualization P.Cignoni, F.Ganovelli, E. Gobbetti, F.Marton, F. Ponchio, R. Scopigno Computer Graphics Forum, 22(3), pp. 505-514, September 2003
For documented and repeatable bugs, feature requests, etc., please use the GitHub issues.
Thanks, support: VCL Informatic department in TU Clausthal, 3D-COFORM. Also to Kai Hormann for having me write the thesis :)
