Animating a camera (or any other FBX object)

Unless you are using blended animation, setting up the data structures required for animation is very straightforward. You’ll need one animation stack; one animation layer; and one animation curve node for every animated property.

Let’s say that you need to animate a camera. More specifically, you want to animate the local translation property of a camera’s KFbxNode object:

KFbxScene* myScene;        // An initialized and valid scene object

KFbxNode* myCameraNode;    // An initialized and valid node object

// Set the default local translation values (X, Y, Z) for the camera

myCameraNode.LclTranslation.Set(fbxDouble3(1.1, 2.2, 3.3))

Although this example deals with the translation of a camera, you can animate any FBX property of any FBX object, providing that the property is animatable (see eFbxPropertyFlags::eANIMATABLE).

You always need at least one stack and one layer

Begin by creating one animation stack:

// Define an animation stack

KFbxAnimStack* myAnimStack = KFbxAnimStack::Create(pScene, "My stack");

You need to define only one animation layer:

// Create the base layer (this is mandatory)

KFbxAnimLayer* myAnimBaseLayer = KFbxAnimLayer::Create(pScene, "Layer0");

Add this layer to the animation stack:

myAnimStack->AddMember(myAnimBaseLayer);

Curve nodes connect animation data to the animated property

CubeCreator creates one animation curve node for each axis along which the camera moves. You need one animation curve node to connect the translation data to the camera node’s lclTranslation property:

// Get the camera’s curve node for local translation.

// true: If the curve node does not exist, create it.

pCamera->LclTranslation.GetCurveNode(pAnimLayer, true);

Notes on animation curve nodes:

myAnimCurveNode was automatically created with three animation channels of type double, because the type of lclTranslation is fbxDouble3. See KFbxNode::lclTranslation.
myAnimCurveNode was automatically connected to myCameraNode.LclTranslation, the local translation property of the camera that we are animating.
myAnimCurveNode was automatically added as a member curve node to myAnimBaseLayer. Animation layers are containers for animation curve nodes.
For another approach to creating animation curve nodes and animation curves, see the Animation sample program in <yourFBXSDKpath>\examples\Animation\

myAnimCurveNode is all set up to connect animation curves to the local translation property of myCameraNode. All that is missing are the animation curves.

KFbxAnimCurve* myTranXCurve = NULL;   // Curve for local translation on X-axis

KTime myTime;                         // For the start and stop keys.

int myKeyIndex = 0;                // Index for the keys that define the curve

// Get the animation curve for local translation of the camera.

// true: If the curve does not exist yet, create it.

myTranXCurve = myCameraNode->LclTranslation.GetCurve<KFbxAnimCurve>

                                  (myAnimLayer, KFCURVENODE_T_X, true);

// First the start keyframe

myAnimCurve->KeyModifyBegin();

myTime.SetSecondDouble(0.0);             // Starting time

myKeyIndex = myAnimCurve->KeyAdd(lTime); // Add the start key; returns 0

myAnimCurve->KeySet(lKeyIndex,           // Set the zero’th key

                    lTime,               // Starting time

                    0.0,                 // Starting X value

KFbxAnimCurveDef::eINTERPOLATION_LINEAR);// Straight line between 2 points

// Then the stop keyframe

lTime.SetSecondDouble(20.0);

lKeyIndex = lCurve->KeyAdd(lTime);

lCurve->KeySet(lKeyIndex, lTime, 500.0, KFbxAnimCurveDef::eINTERPOLATION_LINEAR);

lCurve->KeyModifyEnd();

So if you were to run this animation, the camera would take 20 seconds to move 500 units along the X-axis.