This node represents a 3D shape formed by constructing faces (polygons) from vertices located at the coordinates specified in the vertexProperty field (from OIV.Inventor.Nodes.SoVertexShape), or the current inherited state. For optimal performance, the vertexProperty field is recommended.

OIV.Inventor.Nodes.SoIndexedFaceSet is a general purpose polygon rendering node. It can render triangles, quadrilaterals, and other types of polygons or any combination thereof.

Tips:

• For best performance, arrange the faces with all triangles first, then all quadrilaterals, then general polygons.

• If the shape has only triangles, use OIV.Inventor.Nodes.SoIndexedTriangleSet instead (simpler and possibly faster).

OIV.Inventor.Nodes.SoIndexedFaceSet supports both convex and non-convex polygons (unlike OpenGL). However polygons are assumed to be convex by default. Rendering non-convex polygons in this mode may produce incorrect results. Enable non-convex polygons using the faceType field of an OIV.Inventor.Nodes.SoShapeHints node. In this mode OIV.Inventor.Nodes.SoIndexedFaceSet will automatically convert non-convex polygons, if necessary, to faces that the hardware can handle.

OIV.Inventor.Nodes.SoIndexedFaceSet can also directly handle complex polygons with "holes". See the following paragraphs.

If OIV.Inventor.Nodes.SoShapeHints is not used, or if windingType field from OIV.Inventor.Nodes.SoShapeHints is equal to NO_WINDING_TYPE, OIV.Inventor.Nodes.SoIndexedFaceSet uses the indices in the coordIndex field (from OIV.Inventor.Nodes.SoIndexedShape) to specify simple polygonal faces. An index of SO_END_FACE_INDEX (-1) indicates that the current face has ended and the next one begins.

If OIV.Inventor.Nodes.SoShapeHints is used with a windingType field other than NO_WINDING_TYPE, OIV.Inventor.Nodes.SoIndexedFaceSet uses the indices in the coordIndex field (from OIV.Inventor.Nodes.SoIndexedShape) to specify complex polygonal faces (possibly) made up of multiple contours. An index of SO_END_CONTOUR_INDEX (-1) indicates that the current contour has ended and that the next one begins. An index of SO_END_POLYGON_INDEX (-2) indicates that the current complex face (group of contours) has ended. After the end of a complex face, you can create another complex face, and so on.

The vertices of the faces are transformed by the current transformation matrix. The faces are drawn with the current light model and drawing style. Diffuse color and opacity may be specified using the orderedRGBA field of OIV.Inventor.Nodes.SoVertexProperty. Diffuse color, transparency and other color parameters used in the lighting equation may be specified using OIV.Inventor.Nodes.SoMaterial.

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. PER_VERTEX specifies a material or normal for each vertex. The corresponding _INDEXED bindings are the same, but use the materialIndex or normalIndex indices (see OIV.Inventor.Nodes.SoIndexedShape). The default material binding is OVERALL. The default normal binding is PER_VERTEX_INDEXED.

If any normals (or materials) are specified, Open Inventor assumes you provide 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.

Lighting is enabled by default (see OIV.Inventor.Nodes.SoLightModel). If lighting is enabled, by default only the "front face" of polygons are lit (the back face will be black). Which side is the front face is determined by the normal vector, if specified, else by the ordering of the vertices and the vertexOrdering field of OIV.Inventor.Nodes.SoShapeHints. You can also enable "two sided lighting" using OIV.Inventor.Nodes.SoShapeHints.

If lighting is enabled and no normals are specified, they will be generated automatically. The normal generator computes "facet" or "smooth" (or a combination) normal vectors depending on the creaseAngle field of OIV.Inventor.Nodes.SoShapeHints.

Textures may be applied using (for example) OIV.Inventor.Nodes.SoTexture2. Texture coordinates may be supplied using OIV.Inventor.Nodes.SoVertexProperty or OIV.Inventor.Nodes.SoTextureCoordinate2. If a texture is applied and no texture coordinates were specified, they will be computed automatically. By default the computed coordinates map the texture to the axis-aligned bounding box of the shape, with the texture S axis corresponding to the longest axis of the box.

Warning: The shape may not render or pick correctly if any of its polygons are self-intersecting or non-planar.

Limitations:

• Currently does not use OpenGL VBOs (vertex buffer objects) for rendering (and performance may be lower) when both texture coordinates and texture coordinate indices are specified. Just setting texture coordinates (indexed by the coordIndex values) is OK.

FILE FORMAT/DEFAULT

IndexedFaceSet {

vertexProperty	NULL
coordIndex	-1
materialIndex	-1
normalIndex	-1
textureCoordIndex	-1

}

ACTION BEHAVIOR

OIV.Inventor.Actions.SoGLRenderAction Draws faces based on the current coordinates, normals, materials, drawing style, and so on.

OIV.Inventor.Actions.SoRayPickAction Picks faces based on the current coordinates and transformation. Details about the intersection are returned in an OIV.Inventor.Details.SoFaceDetail.

OIV.Inventor.Actions.SoGetBoundingBoxAction 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.

OIV.Inventor.Actions.SoCallbackAction If any triangle callbacks are registered with the action, they will be invoked for each successive triangle generated from each face in the set.

Reference