[Bf-committers] Blender and laser scanner - amendment

Bastien Montagne montagne29 at wanadoo.fr
Tue Apr 30 14:39:46 CEST 2013


Indeed, adding color CD layer to vertices is not a great deal. For 
render, I think the simplest solution would be to tweak a bit particles 
(we already have billboards, just would have to make them be able to 
take the color from actual vertices and not only from loops), a system 
with as much particles as vertices, emitted from those all at once and 
with lifetime=scene duration is a suitable way to render a points cloud. 
With a decent modern computer, Blender can render several millions of 
such billboards with no problem. :)

And we could also have some tool to convert points clouds to actual 
meshes + textures, which could generate much faster objects for rendering...

So, especially if Jace already did part of the work (btw, Jace, any 
patch, branch or so available?), to get a basic usable and rederable 
solution should not be *that* hard!

Best regards,

On 30/04/2013 01:30, Isaac Lenton wrote:
> Hi
> I looked into this for a project I was working on for visualising point
> clouds generated from computational physics simulations.  I recall that
> I managed to get the points rendering in Blender Render with a few quick
> hacks and duplicating the colour data onto individual vertices (maybe
> not the best idea).  I ended up switching to VTK and ParaView for most
> of my scientific data visualisation, but I would be interested if
> someone were to implement a basic pipeline as described by Jace Priester
> but with a step 6:
>          6) Support for community add-ons (through python) for preforming
>          basic data/point processing/rendering operations.
> ParaView provides a large selection of operators, some of which would be
> trivial to implement in blender if a pipeline was set-up.
> This idea might also be of interest to Shabbir Marzban, whose recent
> GSoC email to the mailing list included a proposal to integrate Bundler:
>          "1) Automated rigid structure reconstruction from set of
>          un-ordered images: A very common structure from motion (SFM)
>          tool, Bundler[1] can be used to recover 3D point cloud from such
>          images."
> Thanks,
> Isaac Lenton
> PS: The mailing list seems to be blocking some of my emails, not sure if
> this will get through.
> On Mon, 2013-04-29 at 15:02 -0700, Jace Priester wrote:
>> I wrote in point cloud support for Blender over a year ago, but I have been
>> told repeatedly by the developers that there is no interest in the
>> community and therefore they aren't interested in implementing it.
>> Hopefully another voice will help with that.
>> The code isn't extensive as is. It requires a custom data layer to support
>> true per-vertex color (as Blender currently implements vertex color as part
>> of face data - not vertex data). There's a bit of extra code in the mesh
>> drawing functions to access the colors in the custom data layer, and then
>> it draws points to the screen using the set colors. As a bonus, it also
>> supports per-vertex sizing which allows for point distance attenuation
>> (which is necessary for a good appearance). My current code does *not*
>> integrate with any rendering engine - it only works in the editor window -
>> and I gave up trying to get help taking it any further, as I don't use it
>> that often anyway.
>> If a developer knowledgeable enough about BI/cycles wants to hop in and
>> help with finishing this, I'd be happy to collaborate. I see no need for
>> blender to be a point cloud editing program. Meshlab and others are better
>> suited to that, as that is specifically what they are built for. But the
>> ability to import and display point cloud data, in my opinion, is vital to
>> Blender being usable in more fields than it is now. So that said, I think
>> short term and easily attainable goals should be to
>> 1) import point cloud data in a couple common formats (I have done this
>> already)
>> 2) display points with colors and distance attentuation (also done)
>> 3) export point cloud data (also done)
>> 4) some user interface controls for turning colors on/off, adjusting
>> displayed vertex size and attenuation (have not done any of this)
>> 5) support for render at least in BI
>> On Mon, Apr 29, 2013 at 2:19 PM, Antoine Cottin<acottin at ultiscan.com>wrote:
>>> Hi y'all,
>>> Sorry for the repost this might be obvious or not, but after re-reading my
>>> previous post, I feel that need to mention that our goal is not to produce
>>> a tool dedicate to our sole use. Our goal is to develop a tool for us and
>>> the Blender community that will be release under GPL.
>>> Cheers.
>>> Antoine
>>> #######
>>> My name is Antoine Cottin, I'm a research scientist specialized in active
>>> remote sensing applied to earth sciences. For the last 8 years I've been
>>> working for/with a laser scanner manufacturer developing processing tools
>>> chain for laser scanner data processing. I have an extended knowledge in
>>> the various laser scanner systems (hardware and software) and their
>>> associated data format.
>>> I'm the founder of Ultiscan, a French base company, specialized in laser
>>> scanning services.
>>> Our main objective/activity at Ultiscan beside laser scanning assets is
>>> data fusion between laser scanner data (points cloud) and 3D assets for 3D
>>> rendering and animation. Here is an example of one of our last project.
>>> This purpose of this project was to merge a 3D asset (the front gate of the
>>> heritage building) with a point cloud of the whole building to show to the
>>> client how the restoration of gate of the building would look like (some
>>> work on texturing is still required):
>>> https://www.dropbox.com/s/u6bj80fi8ajqq8r/00_Gruss_Fusion_100p_Black.mp4
>>> The gate have been mesh, from the laser scanner data, and then
>>> retopologize (from ~2500k faces to 600 faces), texture and render with
>>> Blender. The points cloud animation was done with a commercial software.
>>> Then the two pieces was merged together. To do that, we used Blender for
>>> the camera tracking, the render and the compositing of the final result.
>>> Needless to say that it is doable but a bit tedious. Also, reconstructing
>>> the 3D space from camera tracking defeat the initial purpose of using 3D
>>> laser scanning data which are per essence more dense and most likely more
>>> accurate.
>>> My company, and I, would love to have the points cloud capability
>>> integrate to Blender to being able to generate this kind of animations (but
>>> nicer),
>>> https://www.dropbox.com/s/qrlmt3zq84knlpq/00_Gruss_PointCloud_Animation.m4v
>>> but also to streamline and help with some of the VFX pipeline.
>>> So we did some scripting to test the capability but obviously python
>>> scripting isn't the good approach to read and display millions of points.
>>> It also remain the question on how to efficiently display a points cloud ?
>>> as point cannot be rendered, a turnaround is needed. We tried to put a
>>> small circle at each point of the points cloud but this literally overflow
>>> Blender.
>>> In the shed of our tests, we have to get into Blender development for this
>>> and we are willing to give a try. I've contacted Ton Roosendaal and he told
>>> me to post the idea in here to discuss it's relevance.
>>> I'm a self taught coder and I've been coding for the last 13 years mainly
>>> in IDL/ENVI, which is a dedicate remote sensing/data visualization
>>> language. I've knowledge and more limited expertise's in C and
>>> object-oriented language like python and objective-C.
>>> I think the best way to succeed to such project would be to team-up with
>>> some mentor(s) that already have experience in Blender development. So if
>>> someone is interested in this project, please give us a shout.
>>> Please give us your idea on this project.
>>> Looking forward to discuss this exiting project with you.
>>> Respectfully your.
>>> Dr. Antoine Cottin
>>> -------------------------------
>>> Ultiscan
>>> _______________________________________________
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>>> Bf-committers at blender.org
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