Create surface

Will Schroeder will.schroeder at
Wed Sep 15 13:50:44 EDT 1999

Hi Luis-

At 11:47 AM 9/15/99 +0100, Luis Miguel Gonçalves wrote:
>Greetings!, VTK users,
>         I can already visualize molecules using pdbs in VTK...I have a set of
>points that correspond to types of atoms, and each point represents the
>center of a sphere with the correspondent colour and radius....What I want
>is to create a surface from those spheres...I don't want to see the
>interception of the spheres...I want a smooth surface around them...Can
>anyone help?

Two ideas come to mind. Use the implicit function vtkSphere along with vtkImplicitBoolean, and vtkSampleFunction  to create a union (a sampled volume) of all the "spheres" that make up the molecule, and then isosurface the resulting implicit function (with value=0.0) to get a single surface. Alternatively, you could volume render the sampled volume. Look at the examples graphics/examplesTcl/iceCream.tcl for an example.

Another approach is to use vtkImplicitModeler to create a sampled function (of distance function) and then isosurface/volume render that.

If you're going to volume render you're going to have to convert from float to something the volume renderer can handle (e.g., unsigned short). Also, I'm not sure what you're going to do about coloring the surface.


Dr. William J. Schroeder
Kitware Visualization Solutions / vtk Commercial Support
469 Clifton Corporate Parkway
Clifton Park, NY 12065
will.schroeder at
1-518-371-3971 (Phone & Fax)

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