# Visualize Very large number of Lines, Points/Spheres with High Performance
**URL:** https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353
**Category:** Development
**Created:** [December 28, 2019, 7:00am UTC](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353 "2019-12-28T07:00:30Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@sharon](https://discourse.vtk.org/u/sharon)
#### Post date: [December 28, 2019, 7:00am UTC](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353/1 "2019-12-28T07:00:30Z")
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?
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### Author:  [@michael23](https://discourse.vtk.org/u/michael23)
#### Post date: [December 28, 2019, 6:37pm UTC](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353/2 "2019-12-28T18:37:13Z")
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.
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### Author:  [@sharon](https://discourse.vtk.org/u/sharon)
#### Post date: [December 31, 2019, 4:02am UTC](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353/3 "2019-12-31T04:02:20Z")
Thank you Michael for your reply!
Havent tried, but [vtkGlyph3D](https://vtk.org/doc/nightly/html/classvtkGlyph3D.html) is an arrow, how you make it as spheres an cylinders?
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### Author:  [@michael23](https://discourse.vtk.org/u/michael23)
#### Post date: [December 31, 2019, 1:29pm UTC](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353/4 "2019-12-31T13:29:58Z")
**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.
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### Author:  [@sharon](https://discourse.vtk.org/u/sharon)
#### Post date: [January 12, 2020, 2:55am UTC](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353/5 "2020-01-12T02:55:44Z")
Thank you Michael very much for your sample code!!
I will have a study of this!
Best Regards!