Visualize Very large number of Lines, Points/Spheres with High Performance

Development
1

Dear Experts,

In my situation, i need visualize very large number of Lines, Points/Spheres, with high performance,
Do you have any suggestions?

My current implementation is put group of lines into polyData, then put polyData into multiBlockData,
in the way i can change color for each group of polyData, but seems the performance is not good…

Any suggestions?

2

Hi,

have you already checked out vtkGlyph3D? I use it to visualize a large number of spheres and cylinders. You can still change the scale, color and orientation individually.

3

Thank you Michael for your reply!

Havent tried, but vtkGlyph3D is an arrow, how you make it as spheres an cylinders?

4

Spheres:

// Array for sphere positions
Points = vtkSmartPointer::New();

// Array for sphere radii
radii = vtkSmartPointer::New();
radii->Initialize();
radii->SetName(“radii”);

// Array for sphere colors
colors = vtkSmartPointer::New();
colors->Initialize();
colors->SetNumberOfComponents(4);
colors->SetName(“colors”);

// Set position, radius and color
for (int i = 0; i < NUMBER OF SPHERES; i++)
{
points->InsertNextPoint(X, Y, Z);
radii->InsertNextValue(RADIUS);
colors->InsertNextTypedTuple(R, G, B, ALPHA);
}

// Create an unstructured grid
grid = vtkSmartPointer::New();
grid->SetPoints(points);
grid->GetPointData()->AddArray(radii);
grid->GetPointData()->AddArray(colors);
grid->GetPointData()->SetActiveScalars(“radii”);

// The points should be visualized as spheres
sourceBall = vtkSmartPointer::New();
sourceBall->SetRadius(1);

// Use VTK’s Glyph3D filter to create a single VTK actor
// which includes multiple spheres at certain locations
source = vtkSmartPointer::New();
source->SetColorModeToColorByScalar();
source->SetSourceConnection(spSourceBall->GetOutputPort());
source->SetInputData(grid);
source->SetScaleModeToScaleByScalar();

// Create VTK actor / mapper
vtkSmartPointer mapper = vtkSmartPointer::New();
mapper->SetInputConnection(spSource->GetOutputPort());
mapper->SetScalarModeToUsePointFieldData();
mapper->SelectColorArray(“colors”);
mapper->SetScalarVisibility(true);
actor = vtkSmartPointer::New();
actor->SetMapper(mapper);

Cylinders:

Just replace the sphere source with a cylinder source.

In order to orient the cylinders, create an additional array like this:

normals = vtkSmartPointer::New();
normals->SetNumberOfComponents(3);

Add the normals to the unstructured grid:
grid->GetPointData()->SetNormals(normals);

Moreover, you call the following method for the cylinder source:
source->SetVectorModeToUseNormal();

I hope this helps.

1 Like
5

Thank you Michael very much for your sample code!!
I will have a study of this!

Best Regards!