Envelope

Object Hierarchy | Related C++ Class: Envelope

Envelope

The Envelope object represents an Envelope Operator on an object. For example an envelope
can be used to deform a mesh surface according to changes in the
positions of ChainBones.

It is possible to add an envelope operator to a point Cluster using SceneItem.ApplyEnvelope. It is
also possible to call ApplyEnvelope on an X3DObject, in which case a complete point
cluster is automatically created.

A ClusterProperty is used to
store the influence that each deformer has on each point. This data
can be read and updated from the Object Model via the Envelope.Weights property.

The Envelope Operators on an object can be accessed via the
Primitive.ConstructionHistory
property (see X3DObject.ActivePrimitive).
Alternatively an envelope can be accessed via the SceneItem.Envelopes property on the
Cluster.

'vbscript example how to access and change the weights of an envelope newscene , false set oRoot = Application.ActiveProject.ActiveScene.Root set oSphere = oRoot.AddGeometry( "Sphere", "MeshSurface") set oChainRoot = oRoot.Add3DChain ' apply envelope to geometry set oEnvelope = oSphere.ApplyEnvelope( oChainRoot, siBranch ) ' Here is another way to get this new envelope: set oEnvelope = oSphere.Envelopes(0) ' get 2D array of element/deformer weights aWeights = oEnvelope.Weights.Array ' change the weights so each deformer has equal influence equalWeight = 100 / oEnvelope.Deformers.Count for iElement=lbound(aWeights,2) to ubound(aWeights,2) for iDeformer=lbound(aWeights,1) to ubound(aWeights,1) aWeights(iDeformer,iElement) = equalWeight next next ' after manipulating the weights set the updated ' weights back on the envelope oEnvelope.Weights.Array = aWeights |

//jscript example how to access and change the weights of an envelope var dft newscene(dft, false ) ; var oRoot = Application.ActiveProject.ActiveScene.Root var oSphere = oRoot.AddGeometry( "Sphere", "MeshSurface") ; var oChainRoot = oRoot.Add3DChain() ; //apply envelope to geometry var oEnvelope = oSphere.ApplyEnvelope( oChainRoot, siBranch ) ; //Here is another way to get this new envelope: var oEnvelope = oSphere.Envelopes(0) ; //get 2D array of element/deformer weights var aVBWeights = new VBArray( oEnvelope.Weights.Array ) ; //convert to a jscript (1D) array object var aWeights = aVBWeights.toArray() ; //change the weights so each deformer has equal influence equalWeight = 100 / oEnvelope.Deformers.Count ; for ( iElement = 0 ; iElement < aWeights.length ; iElement++ ) { aWeights[iElement] = equalWeight ; } //after manipulating the weights set the updated //weights back on the envelope oEnvelope.Weights.Array = aWeights |

'vbscript example that demonstrates how to apply an envelope to 'a cluster. 'It demonstrates how the index in the weights array are based on the 'cluster index, but how this can easily be translated to the 'true vertex index newscene ,false set oSphere = ActiveSceneRoot.AddGeometry( "Sphere", "MeshSurface" ) 'Create a cluster that only contains some of the points. 'These are the only points that will be inflenced by the skeleton set oCluster = oSphere.ActivePrimitive.Geometry.AddCluster( _ siVertexCluster, "MyFrontPoints", Array( 18,19,20,25,26,27) ) 'Create the skeleton set oChainRoot = ActiveSceneRoot.Add3DChain set oEffPos = XSIMath.CreateVector3 oEffPos.Set 3,3,3 set oBone1 = oChainRoot.AddBone(oEffPos) set oEnvelope = oCluster.ApplyEnvelope( oChainRoot, siBranch ) aWeights = oEnvelope.Weights.Array for iElement=lbound(aWeights,2) to ubound(aWeights,2) 'Build a string with all the deformer weights strElementWeights="" for iDeformer=lbound(aWeights,1) to ubound(aWeights,1) strElementWeights = strElementWeights & Round( aWeights(iDeformer,iElement), 2) & "," next 'Calculate the index of the point that corresponds to this 'index in the cluster iVertex = oEnvelope.Elements.Item( iElement ) 'an equivalent way to calculate this same result is as follows: 'iVertex = oCluster.Elements.Item( iElement ) logmessage "Cluster element " & iElement & _ " (pnt " & iVertex & ") has weights " & strElementWeights next 'Output of this script is: 'INFO : "Cluster element 0 (pnt 18) has weights 0,50.26,49.74,0," 'INFO : "Cluster element 1 (pnt 19) has weights 0,37.73,62.27,0," 'INFO : "Cluster element 2 (pnt 20) has weights 0,21.99,78.01,0," 'INFO : "Cluster element 3 (pnt 25) has weights 0,41.27,58.73,0," 'INFO : "Cluster element 4 (pnt 26) has weights 0,14.34,85.66,0," 'INFO : "Cluster element 5 (pnt 27) has weights 0,0.29,99.71,0," |