Nexus is a c++/javascript library for creation and visualization of a batched multiresolution mesh structure.
Main features:
- Multiresolution
- Large models
- Textures or color per vertex
- Streaming
- Compression
- WebGL
###Create the .nxs model
Use nxsbuild to create a multiresolution nexus model (.nxs) out of your mesh (.ply):
$ nxsbuild bunny.ply
The result will be bunny.nxs. For large files this may take quite some time. See the man page for all the options, supported input files etc.
###Simplify and/or compress
The model can be compressed, saving aroung 90% of the size. This is most useful for streaming applications.
$ nxsedit bunny.nxs -z -o bunny.nxz
Detailed information about the compression parameters can be found in the man page.
You can get some statistics using nxsedit on the created model: bounding sphere, list of patches created along with their error using nxsedit:
$ nxsedit bunny.nxs -i -n
The .nxs file can be simplified: you can prune the lowest level of the resolution using the -l option.
###Inspect your model.
Nxsview is a simple program for inspecting a .nxs file:
$ nxsview bunny.nxs
You can tune various parameters through the interface, but be sure to read the available options in the man page.
###WebGL
The easiest way to publish the model on the web is to use 3DHOP interface. Alternatively you can use Threejs: there is a minimal example in the html directory of the repository.
It is strongly recommended to use compression for the models (nxsedit -z).
###Library
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.
###Dependencies and Licenses
All Nexus software is free and released under the GPL license (it depends on Qt and VCG lib).
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 , page 199-207 - 2015
Multiresolution structures for interactive visualization of very large 3D datasets (20MB)
Federico Ponchio
Phd Thesis
Batched Multi Triangulation
Paolo Cignoni, Fabio Ganovelli, Enrico Gobbetti, Fabio Marton, Federico Ponchio, Roberto Scopigno
Proceedings IEEE Visualization, page 207-214 - October 2005
Interactive Rendering of Dynamic Geometry
F. Ponchio, K. Hormann
IEEE Transaction on Visualization and Computer Graphics, Volume 14, Number 4, page 914--925 - Jul 2008
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), August 2004, pp. 796-803, (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), Sept. 2003, pp.505-514.
###Support and thanks
Thanks, support: VCL Informatic department in TU Clausthal, 3D-COFORM. Also to Kai Hormann for having me write the thesis :)