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SimulationEnvironment

Object Hierarchy | Related C++ Class: SimulationEnvironment | Supported Parameter List: Environment

Inheritance

SIObject
   ProjectItem
       SimulationEnvironment

Introduced

4.2

Description

The SimulationEnvironment object represents a construct which is used to define a simulation. For now SimulationEnvironment objects are used only for RigidBody simulations. A simulation environment is a set of connection containers, one for each kind of element in the simulation: the rigid body objects, the rigid body constraints and the forces. The environment keeps track of the relationships between the objects in the simulation and determines on which objects the dynamics operator is applied. The dynamics operator solves the simulation for all elements that are in this environment. As well, a TimeControl object determines how the simulation in this environment is played back.

An environment is created as soon as you create a RigidBody object, which you can achieve by using CreateActiveRigidBody or CreatePassiveRigidBody. You can also explicitly create an environment by using CreateEnvironment. SimulationEnvironment object can be retrieved using Scene.ActiveSimulationEnvironment or Scene.SimulationEnvironments.

Methods

Properties

Examples

1. JScript Example

/*
This example illustrates how to create a cached RigidBody simulation and 
apply that cache to animate the simulated objects directly without using
the simulation.
*/
NewScene( null, false );
var oCone = ActiveSceneRoot.AddGeometry( "cone","MeshSurface" );
var oModel = ActiveSceneRoot.AddModel();
oModel.Name = "Model";
var oGrid = oModel.AddGeometry( "grid","MeshSurface" );

// Move the cone
oCone.posy.value = 6.0;

// Modify the grid
oGrid.ulength.value = 24;
oGrid.vlength.value = 24;
oGrid.subdivu.value = 24;
oGrid.subdivv.value = 24;

// The following line creates the SimulationEnvironment object.
CreatePassiveRigidBody( oGrid );
CreateActiveRigidBody( oCone );

CreateForce( "Gravity" );

var oEnvironment = ActiveProject.ActiveScene.ActiveSimulationEnvironment;
var oSimulationTimeControl = oEnvironment.SimulationTimeControl;

// Turn the caching on.
oSimulationTimeControl.caching.value = true;
oSimulationTimeControl.playmode.value = 0; //Standard play mode.

// Simulate
// To make sure that all frames get simulated
for ( i=0; i<100; i++ ) {
   NextFrame();
   Refresh();
}

// Get all models in the scene (getting the identifier of the Scene Root's class = Model)
var sModelClassID = XSIUtils.DataRepository.GetIdentifier( ActiveSceneRoot, siObjectCLSID );
var oModels = FindObjects( "", sModelClassID );

ApplyCurrentEnvironmentCacheToSimulateObjectForModels( oModels );

// The FCurve animated objects
PlayForwardsFromStart();


// This function takes the cached simulation and copies it directly
// on the driven objects as FCurves. It also turns off the simulation
// so that we could
function ApplyCurrentEnvironmentCacheToSimulateObjectForModels( in_models )
{
   var eModels = new Enumerator( in_models );
   var oCurrEnvironment = ActiveProject.ActiveScene.ActiveSimulationEnvironment;

   var oSimulationTimeControl = oCurrEnvironment.SimulationTimeControl;
   // Deactivate the simulation so that objects are driven by their 
   // animation.
   oSimulationTimeControl.Active.Value = false;

   for ( ; !eModels.atEnd(); eModels.moveNext() ) {
       var oCurrModel = eModels.item();
       var oCache = oCurrEnvironment.FindCacheForModel( oCurrModel );
       var oSourceItems = oCache.SourceItems;
       var eSourceItems = new Enumerator(oSourceItems);
       for( ; !eSourceItems.atEnd(); eSourceItems.moveNext() ) {
          var oSourceItem = eSourceItems.item();
          strTarget = oSourceItem.Target;
          if ( oCurrModel.IsEqualTo(ActiveSceneRoot) == false ) {
              // ActionSource keeps the relative name of an
              // animated parameter. We need to prepend the
              // model name if the model owner is not the scene
              // root in order to fetch the parameter.
              strTarget = oCurrModel.Name + "." + strTarget;
          }
          var oTargetParameter = Dictionary.GetObject(strTarget);

          // The RigidBody simulation caches linear acceleration which
          // is not animatable. We won't be copying those values on 
          // the global transform.
          if ( oTargetParameter.Animatable ) {
              var oCachedFCurve = oSourceItem.Source;
              CopyFCurveOnParameter( oCachedFCurve, oTargetParameter );
          }
       }

   }
}

// This function creates a copy of an FCurve on a parameter by creating a new 
// FCurve on the parameter and adding all keys. It will take use the default
// Tangent and Interpolation.
function CopyFCurveOnParameter( in_FCurve, in_Parameter )
{
   var oNewFCurve = in_Parameter.AddFCurve2();
   var oFCurveKeys = in_FCurve.Keys;
   var eFCurveKeys = new Enumerator( oFCurveKeys );
   oNewFCurve.BeginEdit();
   for( ; !eFCurveKeys.atEnd(); eFCurveKeys.moveNext() ) {
       var oCurrentKey = eFCurveKeys.item();
       oNewFCurve.AddKey( oCurrentKey.time, oCurrentKey.value );
   }
   oNewFCurve.EndEdit();
}

2. Python Example

#
#     This example illustrates how to create cached RigidBody simulations, export 
#     that cache as an action source, import it into a new scene, and then 
#     instantiate it as a clip in the new mixer.
#
from win32com.client import constants as c
Application.NewScene( "", 0 )
oRoot = Application.ActiveSceneRoot
oCone = oRoot.AddGeometry( "cone","MeshSurface" )
oModel = oRoot.AddModel()
oModel.Name = "TestModel"
oGrid = oModel.AddGeometry( "grid","MeshSurface" )

# Move the cone
oCone.posy.Value = 6.0

# Modify the grid
oGrid.ulength.Value = 24
oGrid.vlength.Value = 24
oGrid.subdivu.Value = 24
oGrid.subdivv.Value = 24

# The following line creates the SimulationEnvironment object.
Application.CreatePassiveRigidBody( oGrid )
Application.CreateActiveRigidBody( oCone )

Application.CreateForce( "Gravity" )

oEnvironment = Application.ActiveProject.ActiveScene.ActiveSimulationEnvironment
oSimulationTimeControl = oEnvironment.SimulationTimeControl

# Turn the caching on.
oSimulationTimeControl.caching.Value = 1;
oSimulationTimeControl.playmode.Value = 0; #Standard play mode.

# Simulate, making sure that all frames get simulated
i=0
while i < 100 :
   Application.NextFrame()
   Application.Refresh()
   i = i + 1

# Export the action sources
aModelNames = [ "two", "one", "two", "one" ]
sPath = Application.InstallationPath( c.siProjectPath )
for oActionSource in oEnvironment.Caches :
   Application.ExportAction( oActionSource, sPath + "\\Actions\\SimCache" 
       + aModelNames.pop() + ".xsi" )

# Dump the current scene and open a new one
Application.NewScene( "", 0 )
oRoot = Application.ActiveSceneRoot
oCone = oRoot.AddGeometry( "cone","MeshSurface" )
oGrid = oRoot.AddGeometry( "grid","MeshSurface" )

# Reload the sources
oNewAction = Application.ImportAction( oRoot, sPath + "\\Actions\\SimCache" 
   + aModelNames.pop() + ".xsi", "MyImportedAction1", c.siSourceStorageTypeInternal )
Application.AddClip( oRoot, oNewAction )

oNewAction = Application.ImportAction( oRoot, sPath + "\\Actions\\SimCache" 
   + aModelNames.pop() + ".xsi", "MyImportedAction2", c.siSourceStorageTypeInternal )
Application.AddClip( oRoot, oNewAction );

# Playback the results
Application.PlayForwardsFromStart()

See Also

Autodesk Softimage v7.5     <     >