## ChangeGeneratorInputReadPosition

### Introduced

v5.0

### Description

Changes the stack position at which the generator operator reads from its inputs. The generator can read above any of the construction mode markers. For a list of available generator operators, see Generator and Converter Operators

### Scripting Syntax

    ChangeGeneratorInputReadPosition( Operator, ReadPosition, [UnTransferShapesAndEnvelopes] );

### Parameters

Parameter | Type | Description
--- | --- | ---
Operator | String | Specifies the generator operator to modify
ReadPosition | siConstructionMode | Position on which the generator will reconnect. Can be above any construction mode markers.
UnTransferShapesAndEnvelopes | Integer | What to do with any transfered shapes and/or envelope weight properties when the command will reconnect the generator over the primary shape/animation construction mode. It is usually preferred to undo these transfers, since otherwise there could be a double deformation (the envelope is applied to the input and the generated object). Default Value: 2
Possible Values: | Description:
0 | Yes
1 | No
2 | Prompt the user

### Examples

#### JScript Example

    /*
            This example creates a generator operator and then moves
            its read positions across various construction modes.
    */
    NewScene(null, null);
    Sphere = CreatePrim("Sphere", "MeshSurface", null, null);
    //Create a twist operator in modeling construction mode
    TwistOp = ApplyOp("Twist", Sphere, 3, siPersistentOperation, null, 0);
    //Envelope the shere with a Null (animation construction mode),
    //and move the Null so we can see the difference:
    NullObject = GetPrim("Null", null, null, null);
    EnvOp = ApplyFlexEnv(Sphere + ";" + NullObject, false, 2);
    Translate(NullObject, 4, 0, 0, siRelative, siView, siObj, siXYZ, null, null, null, null,
            null, null, null, null, null, 0);
    //Generate a subdivided sphere from this one
    MeshSubdivideWithCenter(null, "sphere", null, siPersistentOperation, siKeepGenOpInputs);
    GeneratorOp = GetValue("polymsh.polymsh.MeshSubdivideWithCenter");
    logmessage( "Construction region after generator creation: " +
                            GetGeneratorInputReadPosition( GeneratorOp ) );
    //Currently, the generated sphere inherits from the animated (result)
    //position, since by default it connects in secondary shape construction mode.
    //We will now move the read point over the modeling marker so it has
    //has twisted but not enveloped positions:
    ChangeGeneratorInputReadPosition( GeneratorOp, siConstructionModeModeling, 0 );
    logmessage( "Construction region after moving in modeling: " +
                            GetGeneratorInputReadPosition( GeneratorOp ) );
    //Transfer the envelope operator onto the generated sphere:
    TransferClusterPropertiesAcrossGenOp("polymsh.polymsh.MeshSubdivideWithCenter", "polymsh",
            "sphere.polymsh.cls.EnvelopWeightCls.Envelope_Weights", "Envelope_Weights", true);
    //Move the read position to animation mode, but specify to untransfer
    //the envelope in order to avoid the double deformation:
    ChangeGeneratorInputReadPosition( GeneratorOp, siConstructionModeSecondaryShape, 0 );
    logmessage( "Construction region after moving back in secondary shape: " +
                            GetGeneratorInputReadPosition( GeneratorOp ) );
    //Output:
    //      INFO : Construction region after generator creation: 3
    //      INFO : Construction region after moving in modeling: 0
    //      INFO : Construction region after moving back in secondary shape: 3

### See Also

GetGeneratorInputReadPosition MoveOperator MoveOperatorBefore MoveOperatorAfter