The MoMesh MoMesh node stores a pointer to the object implementing the mesh interface. It must be set in the scene graph before any data mapping node. There are two different usages of MoMesh MoMesh . The first one is simply passing the pointer to a user defined mesh to the node. This is the setMesh method.

The second one allows you to use the result of a previous representation as the input mesh. This is the connectFrom method.

The MoMesh MoMesh ::setMesh method:

This method is used to store a mesh in the scene graph. The same node is used for storing all types of mesh. This is done by providing one setMesh method for each type of mesh. The following code shows how to use it:

MoMesh* moMesh = new MoMesh;
moMesh->setMesh(&myMesh);
root->addChild(moMesh);

Where myMesh is the object implementing the mesh interface and root is an SoSeparator SoSeparator SoSeparator (or SoGroup SoGroup SoGroup ) containing the scene graph.

When traversed, this node enables the MoMeshElement MoMeshElement state element which is then used by data mapping nodes for retrieving the mesh to use.

	Note: The mesh is not stored as an Open Inventor field (SoField) object because doing so would not bring any benefit from the field functionality and would require creating one field type for each mesh type.

// Create the first MoMesh to store the 3D mesh
MoMesh* moMesh = new MoMesh;
moMesh->setMesh(&myMesh);
root->addChild(moMesh);

// Create an isosurface
MoMeshIsosurface * isosurf = new MoMeshIsosurface;
// set its parameters
isosurf->...
root->addChild(isosurf);

// Create a second MoMesh to connect the result mesh of the isosurface
MoMesh *meshIsosurf = new MoMesh;
meshIsosurf->connectFrom(isosurf);
root->addChild(meshIsosurf);

// The following isoline will appear on top of the isosurface.
MoIsoline* isoline = new MoMeshIsoline;
// set its parameters
isoline->...
root->addChild(isoline);

Scalar sets are stored in the scene graph using one of the MoScalarSetI MoScalarSetI , MoScalarSetIj MoScalarSetIj or MoScalarSetIjk MoScalarSetIjk nodes depending on the type of scalar set. As several scalar sets can be used for the same extraction, the scalar sets are accumulated into the traversal state in an ordered list. Notice that there is one list for each type of scalar set described above. This is necessary because some algorithms will need MiScalardSetI scalar set in some cases and MiScalardSetIjk in other cases. Thus, for each list, the first created scalar set has index 0, the second has index 1 and so on.

Data mapping nodes use this index for retrieving the scalar set to use, for instance, for coloring a surface.

The following code shows how to store three scalar sets in the scene graph:

MoScalarSetI* scalarSetI1 = new MoScalarSetI;
scalarSetI1->setScalarSet(myScalarSetI1);
root->addChild(scalarSetI1);

MoScalarSetI* scalarSetI2 = new MoScalarSetI;
scalarSetI2->setScalarSet(myScalarSet2);
root->addChild(scalarSetI2);

MoScalarSetIjk* scalarSetIjk = new MoScalarSetIjk;
scalarSetIjk->setScalarSet(myScalarSetIjk);
root->addChild(scalarSetIjk);

Vector sets are stored in the scene graph using one of the MoVec3SetI MoVec3SetI , MoVec3SetIj MoVec3SetIj or MoVec3SetIjk MoVec3SetIjk nodes depending on the type of vector set.

Similar to scalar sets, the vector sets are accumulated into the traversal state in an ordered list. Notice that there is one list for each type of vector set described above. This is necessary because some algorithms will need MiVec3dSetI in some cases and MiVec3dSetIjk in other cases. Thus, for each list, the first created vector set has index 0, the second has index 1 and so on. Data mapping nodes use this index for retrieving the vector set to use.

The following code shows how to store three vector sets in the scene graph:

MoVec3SetI* vec3SetI1 = new MoVec3SetI;
vec3SetI1->setVec3Set(myVec3dSetI1);
root->addChild(vec3SetI1);

MoVec3SetI* vec3SetI2 = new MoVec3SetI;
vec3SetI2->setVec3Set(myVec3dSetI2);
root->addChild(vec3SetI2);

MoVec3SetIjk* vec3SetIjk = new MoVec3SetIjk;
vec3SetIjk->setVec3Set(myVec3dSetIjk);
root->addChild(vec3SetIjk);

The MoDataBinding MoDataBinding node can be used to force the data binding per cell or per node when it cannot be automatically detected from the data sets available in the traversal state list. This happens when using hexahedron IJKmeshes which support:

Setting the MoDataBinding MoDataBinding to PER_CELL will force the extractor to look for a MoScalarSetIjk MoScalarSetIjk or MoVec3SetIjk MoVec3SetIjk for passing to the extractor. Setting the MoDataBinding MoDataBinding to PER_NODE will force the extractor to look for a MoScalarSetI MoScalarSetI or MoVec3SetI MoVec3SetI for passing to the extractor. By default, MoDataBinding MoDataBinding is set to AUTO which means that the data binding is automatically found from the mesh structure and from the data sets stored into the scene graph. For meshes other than hexahedron IJK, the data binding node is usually not necessary.

The MoCellFilter MoCellFilter node stores a pointer to the object implementing the cell filter interface. It must be set in the scene graph before any data mapping node. The same node is used for storing all types of cell filter. This is done by providing one setCellFilter method for each type of mesh.

The following code shows how to use it:

MoCellFilter* moCellFilter = new MoCellFilter;
moCellFilter->setCellFilter(&myCellFilter);
root->addChild(moCellFilter);

Where myCellFilter is the object implementing the mesh interface and root is an SoSeparator SoSeparator SoSeparator ( or SoGroup SoGroup SoGroup ) containing the scene graph.

When traversed, this node enables the MoCellFilterElement MoCellFilterElement state element which is then used by data mapping for filtering extractions.

Color mapping means computing a color from a scalar value. This color can then be applied on top of a surface to visualize a scalar set. The color mapping nodes provide an easy way to define a color look-up table. Four types of color mapping nodes are provided.

The MoLegend node displays a colored legend of the current colormap in a rectangle. A name can be assigned to the legend. Min and max values can be set and a list of values can be displayed. The legend can be horizontal or vertical. The colormap node it represents must be stored in the scene graph before the legend node.

When surfaces are drawn using color contouring (see MoMaterial MoMaterial ), each facet of a surface mesh is rendered using OpenGL. For faces with more than three points, OpenGL automatically converts the faces into triangles and performs color interpolation on each triangle individually without taking into account the other vertices and colors of the face.

In the following example, we have created four squares forming a regular mesh with data on each node. The center node as well as all corner nodes have value 1. The other nodes have value 0. On the right side, you can see that the OpenGL coloring shows an orientation of the data field which is not correct. Furthermore, the color at the center of the cell can be 0 or 1 depending on the way the cell is defined.

Figure 2.2. Enhanced coloring on the left and OpenGL coloring on the right

When turning on the enhancedColoring field of MoMaterial MoMaterial , we obtain the result on the left. Here you can see that the symmetry of the cell is kept and that the coloring is similar for each cell and even the value computed at the center seems realistic even if it is interpolated.

Enhanced coloring uses a GLSL shaders to perform the correct color interpolation. It may be time consuming on some graphic boards so it is disabled by default.

You should turn enhanced coloring on in the following conditions:

	Note: Enhanced coloring uses a GLSL shaders to perform the correct color interpolation

All mesh representation nodes inherit from the abstract MoMeshRepresentation MoMeshRepresentation node. They inherit several fields and methods common to all representations decribed below.

	The MoMeshRepresentation is derived from MoMeshBaseRepresentation which manages actions on Meshviz Data Mapping nodes.

Enabling parallel extractions

The parallel field can be used to turn on or off specific optimizations to take advantage of multi processor systems during the extraction process. Some extraction algorithms such as skin or grid plane slice are already optimized to take advantage of multi processor systems. More optimizations will be provided in future versions. The parallel flag is on by default.

	The Intel Threading Building Blocks (TBB) API is used internally to perform some of the optimizations on compatible systems. TBB can be used with other multi threading tools like OpenMP for instance. The parallel field can be turned off to avoid any conflict with other parallel programming techniques

Display the current line mesh as a line set. The lines can be colored using a scalar set defined in the colorScalarSetId inherited field.

Display the current surface mesh as a face set. The faces can be colored using a scalar set defined in the colorScalarSetId inherited field.

Display an isosurface on a scalar set extracted from the current volume mesh. The surface is made up of points having the given value in the given data set. The scalar set used to extract the isosurface is defined by the isoScalarSetId field. This is an index into the list of scalar set elements existing in the traversal state. See the section called “Scalar Set nodes” for more details on indexing scalar sets. The isosurface created can be colored using another scalar set defined in the colorScalarSetId inherited field.

The MoMeshIsosurface MoMeshIsosurface node creates an isosurface extractor to compute the isosurface. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiIsosurfExtractUnstructured MiIsosurfExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshIsosurface MoMeshIsosurface node to use it, for instance, as input to another extraction module. See the section called “Isosurface on a scalar data set ” for more details.

Figure 2.5. Example showing a green isosurface with a transparent red mesh skin. No data set is mapped onto this isosurface

Figure 2.6. Example showing an isosurface with a transparent red mesh skin. The isosurface is extracted from a first scalar dataset and colored with a second one.

Display the skin of the current volume mesh. The skin of a mesh is made up of all the faces that belong to only one cell. The skin created can be colored using a scalar set defined in the colorScalarSetId inherited field.

The MoMeshSkin MoMeshSkin node creates a skin extractor to compute the mesh skin. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored into the scene graph. For instance, when creating an unstructured mesh, the MiSkinExtractUnstructured MiSkinExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshSkin MoMeshSkin node to use it, for instance, as input to another extraction module. See the section called “Mesh skin” for more details.

Figure 2.7. Example showing the skin of a mesh colored by a scalar dataset. The cell edges are also displayed

Display the outline of the current volume or surface mesh. The outline of a mesh is made up of all the edges that belong to only one cell. The outline created can be colored using a scalar set defined in the colorScalarSetId inherited field.

The MoMeshOutline MoMeshOutline node creates a outline extractor to compute the mesh outline. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored into the scene graph. For instance, when creating an unstructured mesh, the MiOutlineExtractUnstructured MiOutlineExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshOutline MoMeshOutline node to use it, for instance, as input to another extraction module. See the section called “Mesh Outline” for more details.

Figure 2.8. Example showing a white mesh outline with a transparent red mesh skin.

Display a logical slice extracted from the current IJK volume mesh. A logical slice is defined by an axis (I, J or K) and an integer sliceIndex. The logical slice created can be colored using another scalar set defined in the colorScalarSetId inherited field.

The MoMeshLogicalSlice node creates a logical slice extractor to compute the logical slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating a regular mesh, the MiLogicalSliceExtractRegular extractor can be retrieved by calling getRegularExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshLogicalSlice node to use it, for instance, as input to another extraction module. See the section called “Logical slice” for more details.

Figure 2.9. Example showing a logical slice with a white mesh outline extracted from an hexahedron IJK mesh containing faults.

Display an interpolated logical slice extracted from the current IJK volume mesh. An interpolated logical slice is defined by an axis (I, J or K) and a floating point sliceValue. The interpolated logical slice created can be colored using another scalar set defined in the colorScalarSetId inherited field.

The MoMeshInterpolatedLogicalSlice node creates an interpolated logical slice extractor to compute the interpolated logical slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating a regular mesh, the MiInterpolatedLogicalSliceExtractRegular extractor can be retrieved by calling getIjkExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshInterpolatedLogicalSlice node to use it, for instance, as input to another extraction module. See the section called “Interpolated Logical slice” for more details.

Display a plane slice extracted from the current volume mesh. A plane slice is defined by an arbitrary plane in 3D (SbPlane). The plane slice created can be colored using a scalar set defined in the colorScalarSetId inherited field.

The MoMeshPlaneSlice MoMeshPlaneSlice node creates a plane slice extractor to compute the plane slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiPlaneSliceExtractUnstructured MiPlaneSliceExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshPlaneSlice MoMeshPlaneSlice node to use it, for instance, as input to another extraction module. See the section called “Plane Slice” for more details.

Figure 2.10. Example showing a plane slice inside a volume mesh represented by a red and transparent mesh skin

Display a fence slice extracted from the current volume mesh. A fence slice is defined by the intersection of several arbitrary planes (the fences). These fences are defined by the fields polyline and direction of the MoMeshFenceSlice class. Each segment of the polyline is extruded along the direction to form a clipped plane slice. Thus, each fence goes through a segment of the polyline. Each plane slice is clipped by the extrusion of the 2 endpoints of each segment in the direction. The fence slice created can be colored using a scalar set defined in the colorScalarSetId inherited field.

The MoMeshFenceSlice node creates a fence slice extractor to compute the fence slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiFenceSliceExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshFenceSlice node to use it, for instance, as input to another extraction module.

Figure 2.11. Example of fence slice with a Z direction vector. A red SoLineSet is used to display the polyline of the fence slice. A transparent mesh skin and the mesh outlines are also displayed.

Display a cylinder slice extracted from the current volume mesh. A cylinder slice is defined by an arbitrary cylinder in 3D (center position, radius and direction vector). The cylinder slice created can be colored using another scalar set defined in the colorScalarSetId inherited field.

The MoMeshCylinderSlice MoMeshCylinderSlice node creates a cylinder slice extractor to compute the cylinder slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiCylinderSliceExtractUnstructured MiCylinderSliceExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshCylinderSlice MoMeshCylinderSlice node to use it, for instance, as input to another extraction module. See the section called “Cylinder Slice” for more details.

Display a sphere slice extracted from the current volume mesh. A sphere slice is defined by an arbitrary sphere in 3D (center position and radius).

The sphere slice created can be colored using another scalar set defined in the colorScalarSetId inherited field.

The MoMeshSphereSlice MoMeshSphereSlice node creates a sphere slice extractor to compute the sphere slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiSphereSliceExtractUnstructured MiSphereSliceExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshSphereSlice MoMeshSphereSlice node to use it, for instance, as input to another extraction module. See the section called “Sphere Slice” for more details.

Display a grid plane slice extracted from the current volume mesh. A grid plane slice is similar to a plane slice but the generated plane is a regular grid on which nodes are evaluated using the probing mechanism. The grid plane slice created can be colored using another scalar set defined in the colorScalarSetId inherited field.

The MoMeshGridPlaneSlice node creates a plane slice extractor to compute the plane slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiGridPlaneSliceExtractUnstructured MiGridPlaneSliceExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshGridPlaneSlice node to use it, for instance, as input to another extraction module. See the section called “Grid Plane Slice” for more details.

Display an elevated plane slice extracted from the current volume mesh. An elevated plane slice is created by extracting a plane slice of the current volume mesh and displaying a volume defined by the elevation of this slice. The plane slice extracted is defined by an arbitrary 3D plane (SbPlane) specified in the plane field. The elevation values are defined using a scalar set defined in the elevationScalarSetId field and can be scaled by the value specified in the scaleFactor field. The volume displayed can be colored using another scalar set defined in the colorScalarSetIdinherited field.

The MoMeshElevatedPlaneSlice node creates a plane slice extractor to compute the plane slice. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiPlaneSliceExtractUnstructured MiPlaneSliceExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshElevatedPlaneSlice node to use it, for instance, as input to another extraction module.

Display a set of isolines extracted from the current surface mesh.

The isolines created can be colored using another scalar set defined in the colorScalarSetId inherited field. You can specify the iso values, the period of major contour lines and line patterns for major and minor contour lines.

The MoMeshIsoline node creates an isoline extractor to compute the isolines. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiIsolineExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshIsoline node to use it, for instance, as input to another extraction module. See the section called “Isolines” for more details.

Display a set of isolines with annotations extracted from the current surface mesh. The isolines created can be colored using another scalar set defined in the colorScalarSetId inherited field. Several parameters control the way annotation text is displayed.

The MoMeshAnnotatedIsoline node creates an isoline extractor to compute the isolines. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiIsolineExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshAnnotatedIsoline node to use it, for instance, as input to another extraction module. See the section called “Isolines” for more details.

Display a clip line extracted from the current surface mesh. A clip line is defined by the intersection of an arbitrary plane in 3D (SbPlane) with the surface.The plane is specified in the plane field. The created clip line can be colored using a scalar set defined in the colorScalarSetId inherited field.

The MoMeshClipLine node creates a clip line extractor to compute the clip line. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiClipLineExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshClipLine node to use it, for instance, as input to another extraction module.

Displays a list of intersection points extracted from the current line mesh. The displayed points are defined by the intersection of an arbitrary plane (SbPlane SbPlane ) and the line.The plane is specified in the plane field. The created points can be colored by using a scalar set defined in the colorScalarSetId inherited field.

Figure 2.12. Example showing 4 intersection points between the red line mesh and the plane defined by the white jack dragger

The MoMeshClipPoint node creates a clip point extractor to compute the clip line. This extractor can be retrieved by calling the getExtractor() method.

This allows retrieving the result of the extract performed internally by the MoMeshClipPoint node and then this result may be used for instance as input to another extraction module.

Display a set of stream lines extracted from the current volume mesh. The stream lines created can be colored using another scalar set defined in the colorScalarSetId inherited field.

The MoMeshStreamline MoMeshStreamline node creates a stream line extractor to compute the stream lines. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored in the scene graph. For instance, when creating an unstructured mesh, the MiStreamlineExtractUnstructured MiStreamlineExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshStreamline MoMeshStreamline node to use it, for instance, as input to another extraction module. See the section called “Stream lines from a vector field data set”for more details.

Figure 2.13. Examples showing a set of streamlines starting from the red circle. These lines are inside a volume mesh represented by a red and transparent mesh skin

Figure 2.14. idem with other position of the streamlines starting points.

Display a vector data set as a set of arrow vectors. Each value of the vector data set is represented by a small arrow located at the cell center for per cell data sets or at the node position for per node data sets.

The vectorSetId field defines the index of the vector set to display. See the section called “Vector Set nodes” for more details on how to store a vector set in the scene graph.

Display a subset of the mesh cells extracted from the mesh as surfaces. The surface created can be colored using another scalar set defined in the colorScalarSetId inherited field. The cell names and node names can be displayed near their position. Node names and cell names are defined in the topology interfaces. By default, they return the cell or node number. Cells can be rendered at their normal size or can be scaled to have a better understanding of their shape independently of their neighbors.

The MoMeshCellShape MoMeshCellShape node creates a cell extractor to compute the cell surface. This extractor can be retrieved by calling the get*Extractor() method corresponding to the type of mesh stored into the scene graph. For instance, when creating an unstructured mesh, the MiCellExtractUnstructured MiCellExtractUnstructured extractor can be retrieved by calling getUnstructuredExtractor().

This allows you to retrieve the result of the extract performed internally by the MoMeshCellShape MoMeshCellShape node to use it, for instance, as input to another extraction module. See the section called “Cell Extraction” for more details.

Figure 2.15. Unstructured mesh displayed by using a MoMeshCellShape on the left part and a MoMeshSkin on the right part.