HexaLab.net: a new online tool for visualization and evaluation of hexahedral mesh

We are proud to present HexaLab.net our new free online tool for inspecting hex meshes.

HexaLab is a WebGL online tool for real time visualization, exploration and assessment of hexahedral meshes that runs directly in your web browser. This visualization tool targets both users and scholars who employ hexmeshes for Finite Element Analysis, can readily check mesh quality and assess its usability for simulations. You can use HexaLab to perform a detailed analysis of the mesh structure, isolating weak points and generate high quality images. 

To this end, we support a wide variety of visualization and volume inspection tools. The system also offers immediate access to a repository containing all the publicly available meshes produced with the most recent techniques for hex mesh generation. 

The system supports hexahedral models in the popular .mesh and .vtk ASCII formats. 

So follow the link and just drop a mesh on that page, and, please, note that meshes are NOT uploaded anywhere. No 3D data will leave your browser and everything will stay local. 

Beside classical slicing (pictured above) in HexaLab there are many visualization techniques are available like for example we have a minecraft-like interactive digging and undigging of individual cells, that allows to pick exactly what cell you want to hide/reveal.

Or you can reveal the interior by a interactive peeling that progressively hides the cells from the external boundaries:

Or you can interactively hide the good shaped cells to reveal only where the bad ones are. Quality of the meshing can be measured using a variety of measures (indeed all the well known Verdict measures, like Scaled Jacobian, distortion, edge ratio, volume, etc.):

Finally remember that it is free to use, but it is always kind to cite its use by referring the companion paper:

"HexaLab.net: an online viewer for hexahedral meshes"
Matteo Bracci, Marco Tarini, Nico Pietroni, Marco Livesu, Paolo Cignoni
(PDF freely available on arxiv)

MeshLab JS 16.01 Tutorial

A new release of MeshLabJS, the javascript version of meshlab is out.

Obviously being a totally client based, run-in-browser application it is sufficient to open its web page to get the latest version. :). For a mesh processing system that runs inside your browser a new version is just the deploy of the html+js code on the server.

Now a very simple tutorial of what you can do with MeshLabJS v16.01: Remeshing, Comparing two meshes and showing the results.

Start it by simply opening the following web page:

http://www.meshlabjs.net

Press CTRL+f (or ⌘+f on OSX) to jump to the find box and type 'torus'. While you type the long list of available filters will reduce to only the ones matching with the typed text (in this case just one).

Click on the 'Create Torus' filter box and it will open to reveal the parameters. Just increase the 'Subdivision' parameter to 64 and press the '▶︎' (apply filter) button and you should see a torus appear on the right.


Click on the Rendering tab and you access to all the different rendering modes. Click on the wireframe icon to enable, for the current layer, the display of the edges of the mesh. In the space below you should see the parameters of the wireframe rendering (color, thickness etc).


Now press CTRL+f (⌘+f on OSX) again and type 'remesh', open the parameters of the 'Voronoi Remeshing' filter, raise to 2 the 'Refine Step' param, and turn off the 'Voronoi Coloring' option; press the apply filter '▶︎' button.  After one sec you should see a new layer appear in the list of the meshes, named something like 'Voronoi Remeshing of Torus'.  There are two meshes superimposed on the right, to see clearly both of them just click on the 'eye' icon to disable/enable the visualization of each layer.  The new mesh is a remeshing done using a simple sampling plus relaxation strategy followed by a Delaunay triangulation of these samples
done in the geodesic metric. The result is a base mesh that is refined and adapted over the original mesh. Enable wireframe for this mesh too and switch between the two layers to see the difference in meshing.

Now we want just to compute the difference between these two mesh. As it is well known basic differnce between 3D surfaces is well captured by Hausdorff Distance. So again  CTRL+f /⌘+f and type 'diff' , in the filter list should appear 'Compute Hausdorff Distance', open the parameter list and set: target mesh as voronoi remeshing of Torus', sample Num as 1.000.000, and check the 'Save Sample' flag'. Then just start the filter ( ▶︎) in a few secs (two secs on my laptop) you will have the (one sided) Hausdorff distance computed. In the lower left log window you should see numerical info about the computed distance, something like:

Hausdorff Distance computed
     Sampled 1008192 pts (rng: 0)  on Torus searched closest on Voronoi Remeshing of Torus 
     min : 0.000000   max 0.005136   mean : 0.001373   RMS : 0.001600 
Values w.r.t. BBox Diag (3.464102)
     min : 0.000000   max 0.001483   mean : 0.000396   RMS : 0.000462

You will notice also that there is another layer 'Haudorff Samples': a 1M point cloud with all the samples computed. For all these samples also the computed distance is stored as a scalar value, called for lazy traditional reasons, quality.

Lets color this point cloud according it with the distance computed.

 CTRL+f /⌘+f and type 'quality' , in the filter list should appear 'Generate Color from Vertex Quality'; apply it to the Hausdorff Samples layer, switch to the rendering tab and access to the parameter of the point rendering (just click on the small down arrow ▾ below the point rendering icon): Choose 'Per Vertex' as 'Color Source' and 'Flat' as 'Shading'. Now you have your nicely colored samples showing the difference between the original torus and the remeshed one.


Finally click on the histogram icon to get some insight on the distribution of the error and a more precise meaning of the color mapping used.

MeshLab in javascript

We are proud to present the first beta, experimental, buggy, incomplete version of MeshLabJS, the client-side, run-in-browser port of MeshLab. 
Yes, a version of MeshLab that runs directly inside the browser.

http://www.meshlabjs.net/

It is still rudimental, very minimal, but yet it is a nice example of how current browsers are able to run C++ code compiled into a javascript (thanks to emscripten) at a pretty decent speed. WebGL (via three.js) is used for the rendering. 
Just to clarify it totally runs inside your browser, no 3D data is transferred to a server for processing, all the computation are done (in javascript) locally. Your data is safe as in a classical desktop app. 
It is a bit more than an experiment, there are only a few tens of filters (more to come!), and no fancy tools, but some classics like the renowned quadric simplifier and radiance scaling rendering mode, are available.

As usual everything is opensource, this time on github. If you like it star it on github and if you need some specific meshlab filter, just ask for it on the github issue page.

MeshLab for iOS

2 Big News:

1. MeshPad has changed name: now its official name is MeshLab for iOS 
2. MeshLab for iOS is available on the App Store!
   And it is free :)

If you have a iPad or an iPhone you can't miss it, go download it and share the news...

We are investing in it, so expect frequent updates. We feel that this kind of support (i.e. tablet) is really great for showing off results to a really broad spectrum of non technically skilled people. Every time that I give to some CH-only guy an iPad to with a gorgeous model ready to be browsed, well, it really pay off much more than asking him to sit down in front of a PC and passing him a mouse...

MeshPad

If you liked MeshLab and you have an iPad or an iPhone, you cannot miss this: an intuitive, cool 3D viewer to show your models. It is able to sustain the interactive browsing of detailed models (usable up to 2M triangles). Perfect for boldly show hi quality 3D scanned stuff to non-technical guys. Soon to be released.

More info can be found both on MeshPad official web page or on the facebook MeshPad page.

The viewer is well integrated in iOs, so it is automatically started whenever you encounter a 3D model in a recognized format (currently just ply stl obj off). It works with models on the web (see the second video) or with other cloud storage services like DropBox.

So for example it is easy to put a bunch of model on your dropbox account, to boldly show off them just when you need on your iPad.

Here are two videos showing MeshPad in action:

Stay tuned for the official release of the app!

MeshLab Video Tutorial

This blog has been quite lazy recently. But now great news!
We are proud to announce the birth of a dedicated YouTube channel for MeshLab tutorials.

 Mr P.'s MeshLab Tutorials

We will upload some new tutorials in the next days. The first one is already online, and it's a basic one about navigation.

Stay in touch for news, and if you want to collaborate, you are welcome!

VAST 2010 MeshLab Tutorial

At VAST 2010 the 11^th  International Symposium on Virtual Reality, Archaeology and Cultural Heritage. (Louvre, Paris, 21-24 Sept. 2010) there will be a full day tutorial of MeshLab.

It will be held by Marco Callieri and Guido Ranzuglia and will cover almost everything of MeshLab, from basic navigation hint to advanced remeshing, measuring and processing tasks. Obviously with a bit of Cultural Heritage pepper here and there.

Target Audience

• People interested in a simple but powerful opensource tool for mesh processing.
• People who need to visualize, edit and convert 3D models.
• People who need small editing, batch process and mesh cleaning.
• People trying to integrate/replace an existing mesh processing pipeline.
• People interested in advanced, custom measuring/processing of 3D models, exploiting state-of-the-art algorithms.

Participants will be given the latest build of the tool plus some test dataset to experiment with the presented features. Bring your own laptop!

RSVP at the FaceBook Event Page