Package com.openinventor.volumeviz.nodes

Class SoVolumeMask

  • All Implemented Interfaces:
    SafeDisposable
    public class SoVolumeMask
extends SoVolumeData
    Volume mask. This node specifies an arbitrary voxel-based region of a volume data set (SoVolumeData). A volume mask is itself a data volume consisting of binary values. Zero values are "false" and non-zero values are "true". A large number of masks may be defined simultaneously, using an SoVolumeMask node for each one, and mask regions may overlap if desired.

    SoVolumeMask is derived from SoVolumeData. Like SoVolumeData it accesses its data through an SoVolumeReader class. I.e. the data may be in a file or in memory (or any data source using a custom volume reader). The mask volume can be any data type, but unsigned byte is currently the most memory efficient representation.

    SoVolumeMask nodes must follow these rules:

    SoVolumeMask can be used to clip the data volume on a per-voxel basis. But the mask mechanism is much more powerful than that. Each region can have its own transfer function (color map) using SoTransferFunction nodes. Each region can also have its own draw style (volume rendering, isosurface or boundary) using SoVolumeDataDrawStyle nodes. Each region, including the original unmasked volume, is only visible if there exists a transfer function (SoTransferFunction) with the same id value.

    Mask regions:

    A single SoVolumeMask node effectively defines two regions:

    • False voxels (where the mask voxel = 0), and
    • True voxels (where is mask voxel != 0).

    Because intersecting regions are allowed, two SoVolumeMask nodes define (up to) four regions:

    • False (where all masks are 0),
    • True only in mask 1,
    • True only in mask 2, and
    • True in more than one mask (intersection region).

    Each additional mask defines one additional region (voxels that are true only in that mask).

    In addition, if there exists a transfer function with the same id as the original volume (SoVolumeData node), the color value from that transfer function is combined with the color value from the mask region's transfer function.

    Transfer functions:

    A separate transfer function can be specified for each of these regions using SoTransferFunction nodes. The transfer function nodes may be placed under the SoVolumeMaskGroup node, but this is not required.

    NOTE: It is not currently possible to specify a different data range for each mask.

    • A transfer function is associated with a specific mask (i.e. with the voxels that are true only in that mask), by setting the SoTransferFunction node's transferFunctionId equal to the mask's dataSetId . If there is no transfer function with the same id as the mask, then that mask is ignored.
    • A transfer function is associated with all "false" voxels (voxels that do not belong to any mask) by setting its transferFunctionId equal to zero. If there is no transfer function with id = 0, then "false" voxels are not rendered.
    • A transfer function is associated with all "intersection" voxels (voxels that belong to more than one mask) by setting its transferFunctionId equal to SoVolumeMaskGroup.TRANSFERFUNCTION_INTERSECTION_ID. If there is no transfer function with this id value, then intersection voxels (if any) are rendered using the default GRAY color map.

    Draw Styles:

    A separate draw style can be specified for each mask region and for the intersection voxels (but not for false voxels) using SoVolumeDataDrawStyle nodes:

    • Unlike transfer functions, a draw style is associated with a mask (voxels that are true only in that mask) by traversal order. In other words, each mask uses the draw style that is current when the mask is traversed. So you need to put SoVolumeDataDrawStyle nodes under the VolumeMaskGroup, alternating draw style, mask, draw style, mask.
    • A draw style is associated with all "intersection" voxels (voxels that belong to more than one mask) by placing it before the SoVolumeMaskGroup node in the scene graph.

    Data Range:

    SoVolumeMask currently does not support separate data ranges for each mask region. The same SoDataRange will be applied on all regions.

    Note that the inherited undefinedValue field is ignored. Setting it has no effect.

    File format/default:

    VolumeMask {

      allocateResourceOnRender false
      data NODATA 0 0 0 UBYTE 8
      dataRGBA false
      dataSetId 1
      dataTransform NULL
      extent -1 -1 -1 1 1 1
      fileName ""
      texturePrecision 0
      undefinedValue NaN
      useCompressedTexture true
      useExtendedData false
      usePalettedTexture true
      useSharedPalettedTexture true
    }

    See Also:
    SoVolumeDataDrawStyle, SoVolumeRender, SoOrthoSlice, SoObliqueSlice, SoVolumeReader, SoVolumeSkin, SoVolumeMask, SoVolumeMaskGroup, SoMultiDataSeparator

    • Constructor Detail

      • SoVolumeMask

        public SoVolumeMask()
        Constructor.

    • Method Detail

      • getDefaultValue

        public boolean getDefaultValue()
        Returns default value of the volume mask.

      • editSurfaceShape

        public int editSurfaceShape​(SoNode surfaceShape,
                            float thickness,
                            double newValue)
        Replace all voxels intersecting the polygons or lines defined by the surfaceShape and given thickness with the specified value. Returns 0 if successful.

        • surfaceShape is defined in the same 3D space as the dataSet.
        • thickness is defined in voxels. The surfaceShape can be deleted after calling this function.
        • Only an SoVolumeMask with data size of 1 (ie. byte or unsigned byte) can be edited.
        • All zero values are set to zero and all non-zero values are set to 1.

        Call startEditing() before calling this method.

        Overrides:
        editSurfaceShape in class SoVolumeData

      • editSolidShape

        public int editSolidShape​(SoNode solidShape,
                          double value)
        Replace all voxels inside the given shape with the specified value. Returns 0 if successful.

        The geometry defined under solidShape must represent a list of closed surfaces otherwise the result is unpredictable. solidShape must not contain any lines or open polyhedrons (polyhedron with shapes). The result is based on the odd-winding rule, so the result is not necessarily the union or the intersection of the closed surfaces. If you want to voxelize lines or single polygons, see also the editSurfaceShape method.

        If the goal is to define a shape which is the results of the intersection/union of multiple closed surfaces, see the SoCSGShape node.

        • solidShape is defined in the same 3D space as the dataSet. The solidShape can be deleted after calling this function.
        • Only VolumeMask with data size of 1 (ie. byte or unsigned byte) can be edited.
        • All zero values are set to zero and all non-zero values are set to 1.

        Call startEditing() before calling this method.

        Overrides:
        editSolidShape in class SoVolumeData

      • setDefaultValue

        public void setDefaultValue​(boolean defValue)
        Set default value of the volume mask. Default is 0.

      • editSubVolume

        public int editSubVolume​(SbBox3i32 subVolume,
                         SoBufferObject userData)
        Replace the contents of a subvolume with the given data. Returns 0 if successful.

        • The subvolume is specified in voxel/cell coordinates.
        • The buffer size (in bytes) must match the subvolume size (in bytes) exactly.
        • Only an SoVolumeMask with data size of 1 (ie. byte or unsigned byte) can be edited. This implies that dataType of userData must be byte or unsigned byte.
        • warning : userData must be an SoCpuBufferBitSet.

        Call startEditing() before calling this method.

        Overrides:
        editSubVolume in class SoVolumeData

      • setProperties

        public void setProperties​(SbVec3i32 dimension,
                          SbVec3i32 tileSize,
                          int border)

      • setIsReadChar

        public void setIsReadChar​(boolean flag)

      • editSubVolume

        public int editSubVolume​(SbBox3i32 subVolume,
                         double value)
        Replace the contents of a subvolume with the specified value. Returns 0 if successful.

        • The subvolume is specified in voxel/cell coordinates.
        • Only an SoVolumeMask with data size of 1 (ie. byte or unsigned byte) can be edited.
        • All zero values are set to zero and all non-zero values are set to 1.

        Call startEditing() before calling this method.

        Overrides:
        editSubVolume in class SoVolumeData