PolygonMesh visualization with color interpolation

[rbregier]

Hi,
I would like to reopen issue 969 (http://dev.pointclouds.org/issues/969) regarding the
choice of a color interpolation method for PolygonMesh (not flat as default).

The solution proposed by Alexandru to use

setShapeRenderingProperties(pcl::visualization::PCL_VISUALIZER_SHADING, pcl::visualization::PCL_VISUALIZER_SHADING_PHONG, "my_mesh_id");

does not work with a PolygonMesh.

The ID of a PolygonMesh is not added to the attribute shape_actor_map_ of PCLVisualizer when addPolygonMesh is called, and thus when calling setShapeRenderingProperties the function quit with error message

"[setShapeRenderingProperties] Could not find any shape with id <%s>" in pcl/visualization/src/pcl_visualizer.cpp line 1435.

Is there a reason why the id of a PolygonMesh is added to the attribute cloud_actor_map_ and not shape_actor_map_ ?
(cf. addPolygonMesh in pcl/visualization/include/pcl/visualization/impl/pcl_visualizer.hpp line 1514)

Thanks,
Romain Brégier

[jspricke]

@aichim can you have a look at it? Thanks!

[rbregier]

In visualization/include/pcl/visualization/pcl_visualizer.h it is written that (line 349) :
Polygon Meshes are represented internally as point clouds with special cell array structures since 1.4

In the code, I can't really find a reason for a PolygonMesh not to be considered as a shape but as a point cloud in PCLVisualizer.
@rbrusu, is there an early developer to remember why this choice, since it seems to break shape rendering properties modification? I didn't found the corresponding commit.

[rbrusu]

I honestly don't remember why we did it like that. If we can avoid breaking the public API, we can use any mechanisms possible for changing things inside.

[rbrusu]

Is there any follow up to this issue?

[VictorLamoine]

Closing as this is now possible thanks to #1241

Code example

#include <pcl/console/parse.h>
#include <pcl/io/vtk_lib_io.h>
#include <pcl/visualization/pcl_visualizer.h>

using namespace pcl::visualization;
PCLVisualizer::Ptr viewer;

void keyboardEventOccurred(const KeyboardEvent& event, void* nothing)
{
  if (event.getKeySym() == "y" && event.keyDown()) // Flat shading
  {
    viewer->setShapeRenderingProperties(PCL_VISUALIZER_SHADING,
                                        PCL_VISUALIZER_SHADING_FLAT, "polygon");
  }
  else if (event.getKeySym() == "t" && event.keyDown()) // Gouraud shading
  {
    viewer->setShapeRenderingProperties(PCL_VISUALIZER_SHADING,
                                        PCL_VISUALIZER_SHADING_GOURAUD, "polygon");
  }
  else if (event.getKeySym() == "n" && event.keyDown()) // Phong shading
  {
    viewer->setShapeRenderingProperties(PCL_VISUALIZER_SHADING,
                                        PCL_VISUALIZER_SHADING_PHONG, "polygon");
  }
}

int main(int argc, char * argv[])
{
  std::vector<int> stl_file_indices = pcl::console::parse_file_extension_argument (argc, argv, ".stl");
  if (stl_file_indices.empty())
  {
    PCL_ERROR ("Please provide one STL file as argument\n");
    return 1;
  }

  pcl::PolygonMesh mesh;
  pcl::io::loadPolygonFileSTL(argv[stl_file_indices[0]], mesh);

  viewer.reset(new PCLVisualizer);
  viewer->registerKeyboardCallback(&keyboardEventOccurred, (void*) NULL);
  viewer->addPolygonMesh(mesh, "polygon");
  viewer->spin();
  return 0;
}

Flat

Phong

[jpapon]

I think this needs to be re-opened if there isn't another issue for it already - the above code gives me the "Could not find any shape with id" error - it seems setShapeRenderingProperties is not looking in the cloud_actor_map_ where meshes are stored.

I just added a search of cloud_actor_map_ in setShapeRenderingProperties, and it works - though I bet this is dangerous and may break other things.

[zkailinzhang]

me too, same error
[setShapeRenderingProperties] Could not find any shape with id !
[setShapeRenderingProperties] Could not find any shape with id !
[setShapeRenderingProperties] Could not find any shape with id !

[VictorLamoine]

I confirm the behavior, something is broken

[ShangxuanWu]

Is this issue fixed now?

[soulslicer]

Still broken.

[SergioRAgostinho]

Pull requests are welcome.

[ricshaw]

This is also broken in setPointCloudRenderingProperties with a PolygonMesh. See code below:

viewer->addPolygonMesh(input_mesh_,"input_mesh",0);
viewer->setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_SHADING,
pcl::visualization::PCL_VISUALIZER_SHADING_GOURAUD, "input_mesh",0);

This gives the error Unknown property (7) specified! However it does work with the PCL_VISUALIZER_COLOR property, just not the shading property.