## CreateUserMotion

### Introduced

v10.5 (2012)

### Description

Creates a user motion property. User motions are used to control motion vectors on vertices of an object's geometry. User motions can only be created on vertex clusters. A user motion property stores three floating point values for each vertex of the cluster. When a user motion property is applied to an object, the motion blur is no longer computed and instead uses the motion data from this property.

### Scripting Syntax

    oReturn = CreateUserMotion( [InputObjs], [PropertyName], PropPresetObj );

### Return Value

Returns an XSICollection of the newly created properties.

### Parameters

Parameter | Type | Description
--- | --- | ---
InputObjs | String | List of objects or complete point clusters Default Value: Current selection
PropertyName | String | Name of the user motion property Default Value: "UserMotion"
PropPresetObj | Preset object | User motion property preset Default Value: "User Motion Property" preset

### Examples

#### JScript Example

    /*
            This JScript example illustrates how to set the user motion vectors on
            the UserMotion Cluster Property with ICE. The motion vectors of a static
            cylinder are set by the motion of an animated cylinder.
    */
    // Create the cylinders
    NewScene(null, false);
    CreatePrim("Cylinder", "MeshSurface");
    Duplicate("cylinder");
    // Animate the cylinder
    Translate(null, -8, 5, 0);
    SaveKeyOnKeyable("cylinder1", 1);
    Translate(null, 16, 0, 0);
    SaveKeyOnKeyable("cylinder1", 25);
    Translate(null, 0, -10, 0);
    SaveKeyOnKeyable("cylinder1", 50);
    Translate(null, -16, 0, 0);
    SaveKeyOnKeyable("cylinder1", 75);
    Translate(null, 0, 10, 0);
    SaveKeyOnKeyable("cylinder1", 100);
    SelectObj("cylinder", null, true);
    // Add a User Motion Cluster Prop on the static cylinder and set its ICE Tree
    CreateUserMotion();
    var oICETreeColl = CreateSimulatedICETree("cylinder", siNode, null);
    var oICETree = oICETreeColl.Item(0);
    AddICENode("GetDataAtPreviousFrameNode", oICETree);
    SetValue(oICETree + ".GetDataAtPreviousFrameNode.reference", "cylinder1.PointPosition");
    AddICENode("GetDataAtPreviousFrameNode", oICETree);
    SetValue(oICETree + ".GetDataAtPreviousFrameNode[1].reference", "cylinder1.kine.local");
    AddICENode("MultiplyVectorByMatrixNode", oICETree);
    ConnectICENodes(oICETree + ".MultiplyVectorByMatrixNode.vector", oICETree + ".GetDataAtPreviousFrameNode.value");
    ConnectICENodes(oICETree + ".MultiplyVectorByMatrixNode.matrix", oICETree + ".GetDataAtPreviousFrameNode[1].value");
    AddICENode("GetDataNode", oICETree);
    SetValue(oICETree + ".SceneReferenceNode.reference", "cylinder1.PointPosition", null);
    AddICENode("GetDataNode", oICETree);
    SetValue(oICETree + ".SceneReferenceNode[1].reference", "cylinder1.kine.local", null);
    AddICENode("MultiplyVectorByMatrixNode", oICETree);
    ConnectICENodes(oICETree + ".MultiplyVectorByMatrixNode[1].vector", oICETree + ".SceneReferenceNode.value");
    ConnectICENodes(oICETree + ".MultiplyVectorByMatrixNode[1].matrix", oICETree + ".SceneReferenceNode[1].value");
    AddICENode("SubtractNode", oICETree);
    ConnectICENodes(oICETree + ".SubtractNode.first", oICETree + ".MultiplyVectorByMatrixNode.result");
    ConnectICENodes(oICETree + ".SubtractNode.second", oICETree + ".MultiplyVectorByMatrixNode[1].result");
    AddICENode("DivideByScalarNode", oICETree);
    ConnectICENodes(oICETree + ".DivideByScalarNode.value", oICETree + ".SubtractNode.result");
    SetValue(oICETree + ".DivideByScalarNode.divideby", 2, null);
    AddICECompoundNode("Set Data", oICETree);
    SetValue(oICETree + ".Set_Data.Reference", "cylinder.cls.UserMotionCls.UserMotion.Motions", null);
    AddICENode("SwitchContextNode", oICETree);
    ConnectICENodes(oICETree + ".SwitchContextNode.value", oICETree + ".DivideByScalarNode.result");
    ConnectICENodes(oICETree + ".Set_Data.Value", oICETree + ".SwitchContextNode.result");
    ConnectICENodes(oICETree + ".port1", oICETree + ".Set_Data.Execute");
    // Draw a render region with motion blur on, and playback the scene
    RenderRegionCreate(siViewportB, 0, 1, 0, 1);
    SetValue("Views.ViewB.RenderRegion.MotionBlur", true, null);
    PlayForwardsFromStart();

### See Also

AddProp ClusterProperty