There are developments in the area of OPEN INVENTOR  , which are leading to incorporate the VRML 2.0 node types in OPEN INVENTOR. Template Graphics Inc under license from Silicon Graphics Inc the inventor of OPEN INVENTOR started enhancing the library to include VRML 2.0 nodes in its version of OPEN INVENTOR for WIN 32 . The following are the observations from these developments :
 

• Realease 2.2 of OPEN INVENTOR from TGS has the support for VRML 2.0 nodes.
• It has become a necessity for future applications to export VRML 2.0 format, so TGS has  Open Inventor handles this, allowing the application to construct a VRML 2.0 scene graph using the convenient Open Inventor classes and rely on Open Inventor’s built-in persistence capability (SoWriteAction) to generate the corresponding file. Applications can create VRML 2.0 scene graphs directly using the VRML 2.0 node classes.
• Applications can also translate their Open Inventor scene graphs into VRML 2.0 by using SoCallbackAction’s triangle callback to convert complex geometry into IndexedFaceSets. Applications can also use the newly enhanced file translator utility "ivtovrml" to convert Open Inventor files into VRML 2.0 files.
• With the VRML 2.0 nodes it is now possible to create files containing objects that respond to user actions including mouse motion, button clicks, and viewer position. For example, a VRML 2.0 file can be created where an animation is triggered by the user clicking on a certain object (see SoVRMLTouchSensor) or simply by the camera moving into a specified region (see SoVRMLProximitySensor).
• Here are some comparisions of the new developments :

            #Inventor V2.1 ascii
                    Separator {
                        Material { diffuseColor 1 0 0 }
                                Cone {}
                            }
 

            The equivalent VRML 2.0 scene graph to display a red cone

            #VRML V2.0 utf8
                Transform {
                    children Shape {
                        appearance Appearance {
                            material Material { diffuseColor 1 0 0 }
                                                }
                                geometry Cone {}
                                    }
                                 }
 

               The C++ code that creates the traditional Open Inventor "red cone" scene graph
                // Classic Open Inventor nodes
                    SoSeparator *pRoot = new SoSeparator;
                    SoMaterial  *pMat  = new SoMaterial;

                    pMat->diffuseColor.setValue( 1, 0, 0 );
                    pRoot->addChild( pMat );

                    pRoot->addChild( new SoCone );
 

               The New Open Inventor with VRML2.0 nodes

                // VRML 2.0 nodes
                    SoVRMLTransform  *pRoot  = new SoVRMLTransform;
                    SoVRMLShape      *pShape = new SoVRMLShape;
                    SoVRMLAppearance *pApp   = new SoVRMLAppearance;
                    SoVRMLMaterial   *pMat   = new SoVRMLMaterial;

                    pMat->diffuseColor.setValue( 1, 0, 0 );
                    pApp->material.setValue( pMat );
                    pShape->appearance.setValue( pApp );
                    pShape->geometry.setValue( new SoVRMLCone );

                    pRoot->addChild( pShape );
 
 

• How ever there are some limitations to the VRML 2.0 nodes supported in the newer verion of the TGS Open Inventor

            .
 

AudioClip:         Not implemented.
Background:      Not implemented by viewers, but application can implement.
Billboard:           Functions correctly as a grouping node, but does not auto-rotate the geometry.
Collision:            Functions correctly as a grouping node, but collideTime eventOut is not implemented.
                         Note that Open Inventor 2.4 supports collision detection, but it is the application's responsibility to use it  or not.
CylinderSensor: Not implemented.
Extrusion:          Not implemented.
Fog:                  Not implemented.
FontStyle:          horizontal, leftToRight and topToBottom fields not implemented.
                         Only horizontal justification is implemented.
ImageTexture:   Open Inventor will only try to open the first URL specified (app can override).
Inline:                Open Inventor will only try to open the first URL specified (app can override).
MovieTexture:   Not Implemented.
PlaneSensor:      Not Implemented.
PointLight:          radius field not implemented (acceptable per VRML97 section 7.3.3)
Script:                Not implemented.
Sound:               Not implemented.
SphereSensor:    Not implemented.
SpotLight:          radius and beamWidth fields not implemented (acceptable per VRML97 7.3.3)
Text:                  The maxExtent field is not implemented.
TextureTransform: Transformations are applied in the (more intuitive) pre-ISO order.
TouchSensor:      The isOver event is only generated while one of the mouse buttons is depressed.
                           The XXX_changed events are not generated unless isActive is TRUE, in other words, only while a mouse button is pressed.

Viewpoint:           The "binding" behavior is not implemented.
 

• Another important approach however may be the following :

                Write a performer loader which reads VRML 2.0 files directly rather than to convert them to Open Inventor
 

CONCLUSIONS :

  The TGS version of OPEN INVENTOR files cannot be read by the pfnav since the OPEN INVENTOR libraries are made for the WIN 32

 

I N D E X