FreeMat

- Main Page
- Related Pages

vtkUnstructuredGridVolumeRayCastIterator

Section: Visualization Toolkit Volume Rendering Classes

# Usage

vtkUnstructuredGridVolumeRayCastIterator is a superclass for iterating over the intersections of a viewing ray with a group of unstructured cells. These iterators are created with a vtkUnstructuredGridVolumeRayCastFunction.

To create an instance of class vtkUnstructuredGridVolumeRayCastIterator, simply invoke its constructor as follows

      obj = vtkUnstructuredGridVolumeRayCastIterator

# Methods

The class vtkUnstructuredGridVolumeRayCastIterator has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, `obj` is an instance of the vtkUnstructuredGridVolumeRayCastIterator class.

- `string = obj.GetClassName ()`
- `int = obj.IsA (string name)`
- `vtkUnstructuredGridVolumeRayCastIterator = obj.NewInstance ()`
- `vtkUnstructuredGridVolumeRayCastIterator = obj.SafeDownCast (vtkObject o)`
- `obj.Initialize (int x, int y)` - Initializes the iteration to the start of the ray at the given screen coordinates.
- `vtkIdType = obj.GetNextIntersections (vtkIdList intersectedCells, vtkDoubleArray intersectionLengths, vtkDataArray scalars, vtkDataArray nearIntersections, vtkDataArray farIntersections)` - Get the intersections of the next several cells. The cell ids are stored in `intersectedCells` and the length of each ray segment within the cell is stored in `intersectionLengths`. The point scalars `scalars` are interpolated and stored in `nearIntersections` and `farIntersections`. `intersectedCells`, `intersectionLengths`, or `scalars` may be `NULL` to supress passing the associated information. The number of intersections actually encountered is returned. 0 is returned if and only if no more intersections are to be found.
- `obj.SetBounds (double , double )` - Set/get the bounds of the cast ray (in viewing coordinates). By default the range is [0,1].
- `obj.SetBounds (double a[2])` - Set/get the bounds of the cast ray (in viewing coordinates). By default the range is [0,1].
- `double = obj. GetBounds ()` - Set/get the bounds of the cast ray (in viewing coordinates). By default the range is [0,1].
- `obj.SetMaxNumberOfIntersections (vtkIdType )`
- `vtkIdType = obj.GetMaxNumberOfIntersections ()`