- All Implemented Interfaces:
public class SoVolumeFaceSet extends SoFaceSetPolygonal face shape node for volume data. This node defines a shape which is the intersection of the volume data defined by an
SoVolumeDatanode and the 3D shape formed by constructing faces (polygons) from vertices located at the coordinates specified in the
SoVertexShape) or the current inherited state. For optimal performance, use of the
vertexPropertyfield is recommended.
The shape defined by this intersection is textured using the data from the current
interpolationfield controls how the texture is interpolated. Texture coordinates are automatically computed for each vertex based on its position relative to the 3D extent of the volume. If texture coordinates are specified, they are ignored.
This node can be used to create custom "slices" through the volume, for example a cylinder slice. It can be considered a generalization of the
SoFenceSlice, etc features. But note:
- Compared to an equivalent standard slice (e.g.
SoOrthoSlice), the rendering may be slightly different due to positioning and interpolation.
- The standard slices (e.g.
SoOrthoSlice) have "two-sided lighting" enabled by default as a convenience. This is not true for volume geometry nodes (which have the same default as their corresponding standard geometry node), so the "back" side of the geometry will not be lighted unless you enable two-sided lighting using an
This node uses 3D texturing and is not available if the hardware does not support this feature.
SoVolumeFaceSetuses the coordinates in order, starting with the first one. Each face has a number of vertices specified by a value in the
numVerticesfield. For example, an
numVerticesof [3,4,4] would use coordinates 1, 2, and 3 for the first face, coordinates 4, 5, 6, and 7 for the second face, and coordinates 8, 9, 10, and 11 for the third. For improved performance, arrange all the faces with only 3 vertices at the beginning of the list, then all faces with 4 vertices, and finally all other faces.
The number of values in the
numVerticesfield indicates the number of faces in the set.
The coordinates of the face set are transformed by the current cumulative transformation. The faces are drawn with the current light model and drawing style.
Treatment of the current material and normal binding is as follows: The PER_PART and PER_FACE bindings specify a material or normal for each face. The _INDEXED bindings are equivalent to their non-indexed counterparts. The default material binding is OVERALL. The default normal binding is PER_VERTEX.
If any normals (or materials) are specified, Open Inventor assumes you have provided the correct number of them, as indicated by the binding. You will see unexpected results if you specify fewer normals (or materials) than the shape requires. If no normals are specified, they will be generated automatically.
- A face set may render or pick incorrectly if any of its polygons are self-intersecting or non-planar.
- The volume size and orientation (like geometry) can be modified by transformation nodes in the scene graph and this in turn modifies the appearance of volume rendering nodes like
SoVolumeFaceSet. However the same transformation must be applied to the volume data node and all volume rendering nodes associated with that volume. So effectively any transformation nodes that affect the volume must be placed before the volume data node.
- For performance concerns, an instance of
SoVolumeFaceSetshould not be used multiple times in the scene graph. In order to have the best trade-off between performances and memory footprint use a single
SoVertexPropertynode shared by several instances of
- Composition with Multiple Data:
It is possible to compose datasets that have different dimensions, tile sizes and transformations.
In order to help fetch the correct data values in custom shaders, texture coordinates conversion functions are provided in the VolumeViz/vvizStructure.h shader include.
vec3 VVizTextureToTextureVec(in VVizDataSetId datasetSrc, in VVizDataSetId datasetDst, in vec3 texCoord);
The conversion is based solely on the transformations applied to each dataset, which are defined by their model matrix and their extent.
Please note that the model matrix of a dataset is defined by to the
SoTransformationnodes that are placed before the
SoDataSetnode in the order of the traversal.
vertexProperty NULL startIndex 0 numVertices -1 clipGeometry true offset 0 interpolation LINEAR
Draws faces based on the current coordinates, normals, materials, drawing style, and so on.
Computes the bounding box that encloses all vertices of the face set with the current transformation applied to them. Sets the center to the average of the coordinates of all vertices.
If any triangle callbacks are registered with the action, they will be invoked for each successive triangle generated from each face in the set.
Nested Class Summary
Nested Classes Modifier and Type Class Description
SoVolumeFaceSet.InterpolationsDeprecated.As of Open Inventor 188.8.131.52.
Nested classes/interfaces inherited from class com.openinventor.inventor.nodes.SoShape
Nested classes/interfaces inherited from class com.openinventor.inventor.nodes.SoNode
Fields Modifier and Type Field Description
clipGeometrySpecifies to clip the geometry at the volume boundaries.
offsetSets an offset value used for computing the texture coordinates.
Constructors Constructor Description
Methods inherited from class com.openinventor.inventor.nodes.SoVertexShape
Methods inherited from class com.openinventor.inventor.nodes.SoShape
getShapeType, isPrimitiveRestartAvailable, isPrimitiveRestartAvailable
Methods inherited from class com.openinventor.inventor.nodes.SoNode
affectsState, callback, copy, copy, distribute, doAction, getAlternateRep, getBoundingBox, getByName, getMatrix, getPrimitiveCount, getRenderEngineMode, getRenderUnitID, GLRender, GLRenderBelowPath, GLRenderInPath, GLRenderOffPath, grabEventsCleanup, grabEventsSetup, handleEvent, isBoundingBoxIgnoring, isOverride, pick, rayPick, search, setOverride, touch, write
Methods inherited from class com.openinventor.inventor.fields.SoFieldContainer
copyFieldValues, copyFieldValues, enableNotify, fieldsAreEqual, get, getAllFields, getEventIn, getEventOut, getField, getFieldName, hasDefaultValues, isNotifyEnabled, set, setToDefaults
Methods inherited from class com.openinventor.inventor.misc.SoBase
dispose, getName, isDisposable, isSynchronizable, setName, setSynchronizable
public final SoSFBool clipGeometrySpecifies to clip the geometry at the volume boundaries.
SoROInode also affects the clipping process. Default is true.
public final SoSFFloat offsetSets an offset value used for computing the texture coordinates.
The texture coordinate for each vertex will be taken from a point offset units away from the vertex. The offset is measured in the direction of the vertex normal. By default the offset is equal to 0 (no offset). When using this feature, a vertex normal must exist for every vertex. If vertex normals are not supplied, Open Inventor will compute vertex normals in the usual way except that the crease angle will be fixed at PI in order to assure that a vertex normal is computed at every vertex.