[Meshlab-devel] point based stuff

[Gael G. <g....@fr...>]

Hi all,

to keep everybody up to date, I think it is time to present a bit the point
based related stuffs I recently added in meshlab, so here you go:

1 - a high quality splatting renderer to quickly render point clouds
equipped with normals. (in meshlabplugins/splatrenderer)

It implements a perspective accurate splatting algorithm with deferred
shading for high quality phong shading. You can scale the size of the
splats, as usual, with alt+wheel.

To try it, open src/sample/chameleon4k.pts or src/sample/bunny16.pts, and
select Render->Shaders->splatting (those two models are very sparse, so no
high quality here ! ).

As any piece of code which highly relies on somewhat advanced hardware
features, it is likely to not work on any systems yet. So I'll be happy to
get feedback on systems other than Linux + nvidia 8x00 (which should work
well) and Linux + ATI (which does not work because of a 5 years old bug in
ATI cards/drivers).


2 - MLS based surface reconstruction and smoothing. (in
meshlabplugins/mlsfilter)

These filters are in Filters->Point Set and they implement APSS which is
based on spherical fit (it can also do plane fit by setting the spherical
parameter to 0). The other one called ##### is experimental.

To try it, open src/sample/chameleon4k.pts, look a bit at the very low
sampling density of the model, do a marching cube extraction with APSS and
change the parameters to:
 - Filter scale = 2.1
 - grid resolution = 750 (here we need a dense grid to capture the fine
parts of the model)
and wait a couple of seconds... It also work very well at noise removal. In
that case you'll have to increase the filter scale parameter to increase the
smoothness (and computation time !).

The "projection" filter project a mesh/points onto the MLS surface. You can
project a mesh/points on itself but in that case the initial MLS surface is
lost (because after the projection the points/vertices define a different
surface). So in practice is is better to first clone the model.

cheers,
gael.