FBX Node Attributes

Creating a Node Attribute

A KFbxNodeAttribute is paired with a KFbxNode to define a scene element with a specific position, rotation and scale. Calling KFbxNode::GetNodeAttribute() will return NULL if no node attribute was set for that node.

The following code sample (adapted from ExportScene04/main.cxx to fit the diagram above) illustrates how to create a simple spotlight within a scene. Here, KFbxLight* light is the node attribute of KFbxNode* lightNode. For more information on lights, see Lights.

// Create a spotlight. 
KFbxNode* CreateLight(KFbxScene* pScene, char* pName)
{
    KFbxLight* light = KFbxLight::Create(pScene,pName);

    light->LightType.Set(KFbxLight::eSPOT);
    light->CastLight.Set(true);

    KFbxNode* lightNode = KFbxNode::Create(pScene,pName);

    lightNode->SetNodeAttribute(light);

    return lightNode;
}

Node Attributes

The following table presents a set of basic scene elements and their related KFbxNodeAttribute subclasses. These node attributes can be paired with a KFbxNode using KFbxNode::SetNodeAttribute(). Consult the C++ Reference guide for the full class hierarchy.

Scene Element	KFbxNodeAttribute subclass
Camera	KFbxCamera, KFbxCameraStereo
Camera Switcher (custom camera definition in Autodesk MotionBuilder)	KFbxCameraSwitcher
Line	KFbxLight
Mesh	KFbxMesh
Nurb	KFbxNurb, KFbxNurbsCurve, KFbxNurbsSurface, KFbxTrimNurbsSurface
Patch / Parametric Surface	KFbxPatch
Level of Detail Group	KFbxLodGroup
Marker	KFbxMarker
Skeleton	KFbxSkeleton

NoteSome applications require a null node type in their scene graph. The KFbxNull node attribute is used to define such a node type. Observe that an instance of KFbxNull is not the same as the NULL value.

Node Attribute Type

The type (KFbxNodeAttribute::EAttributeType) of a KFbxNodeAttribute can be obtained by calling KFbxNodeAttribute::GetAttributeType(). The EAttributeType is useful for downcasting the node attribute object to its appropriate subclass.

The following code sample (adapted from ImportScene/main.cxx and ImportScene/DisplayLight.cxx) illustrates how to use a switch to display a KFbxLight contained in a KFbxNode.

//
// Adapted from ImportScene/DisplayLight.cxx ...
// Display the various properties of the KFbxLight contained within the KFbxNode.
//
void DisplayLight(KFbxNode* pNode)
{
    KFbxLight* lLight = (KFbxLight*) pNode->GetNodeAttribute();

    DisplayString("Light Name: ", (char *) pNode->GetName());
    // ...

    char* lLightTypes[] = { "Point", "Directional", "Spot" };

    DisplayString("    Type: ", lLightTypes[lLight->LightType.Get()]);
    DisplayBool("    Cast Light: ", lLight->CastLight.Get());

    if (!(lLight->FileName.Get().IsEmpty()))
    {
        DisplayString("    Gobo");

        DisplayString("        File Name: \"", lLight->FileName.Get().Buffer(), "\"");
        DisplayBool("        Ground Projection: ", lLight->DrawGroundProjection.Get());
        DisplayBool("        Volumetric Projection: ", lLight->DrawVolumetricLight.Get());
        DisplayBool("        Front Volumetric Projection: ", lLight->DrawFrontFacingVolumetricLight.Get());
    }

    // ...
}

//
// Adapted from ImportScene/main.cxx ...
// Display the contents of a node. Here, we are only interested in
// looking  at the eLight attribute type, which coincides with the 
// KFbxLight node attribute.
//
void DisplayContent(KFbxNode* pNode)
{
    KFbxNodeAttribute::EAttributeType lAttributeType;
    int i;

    if(pNode->GetNodeAttribute() == NULL)
    {
        printf("NULL Node Attribute\n\n");
    }
    else
    {
        lAttributeType = (pNode->GetNodeAttribute()->GetAttributeType());

        switch (lAttributeType)
        {
            // ...

        case KFbxNodeAttribute::eLIGHT:     
            DisplayLight(pNode);
            break;

            // ...
        }
    }

    // ...

    for(i = 0; i < pNode->GetChildCount(); i++)
    {
        DisplayContent(pNode->GetChild(i));
    }
}

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