Hello 
I am creating a 3D viewer to display large point cloud, I want to add octree structure to my viewer. This octree must allow me :
Is there a vtk class that allows me to have this both functionnality in a single octree structure (according to what I found vtk octree is used to find closest neighbour) or should I use potree library ( or create my own octree algorithm and data structure) ?
Thanks for your help
vtkStaticPointLocator ?
@mwestphal with vtkStaticPointLocator you can locate a point but I also want to choose de LOD to render to optimize performance and according to the documentation this class does not have such a functionnality or maybe I don’t look at the doc correctly
Indeed, LOD would need to be performed using a dedicated filter for LOD.
@mwestphal do you know what kind of filter ? Could I use the same octree with this filter that I create with vtkStaticPointLocator? I am starting to use vtk, it’s not easy to see the power of filters
There are several decimators. Also check out vtkBinnedDecimation (which is similar to what ParaView uses).
Paraview uses vtkBinnedDecimation as filter to display LOD ? Because Paraview octrees seem to be very efficient. I should maybe go deeper inside the paraview source code to see how octrees are managed
ParaView use VTKm provided decimator.
@mwestphal So with a decimator filter, LODMapper and LODActor I should be able to have performance equivalent to paraview octree ?
Probable a bit basic for you but some of the octree examples may help e.g. OctreeVisualize, there are nine other examples there.
Yes I’ve already seen this example, it displays an octree representation according to the choosen level but you can’t display the corresponding point. I am running through the vtk documentation and examples and honestly for now I’m not totally convinced that using the vtk classes allows me to generate a real octree structure for displaying and finding points.
When I use vtkBinnedDecimation, I get the error “no data to decimate”, is it posible to apply such a decimator with vtkPoints ?
No, it’s a mesh decimation algorithm
If I want to decimate a pointcloud (vtkpoints), is there some vtk tools to do that or should I do that by my own ?