By default, the RotateAngleToValue property is empty. If the RotateAngleToValue property is empty, missing or invalid, it has no effect. If the RotateAngleToValue property is valid, the result of evaluation of the RotateAngleToValue property indicates the layer's Value property. The ValueToRotateAngle property converts the value back to a rotation angle. Use the DefaultLayer(exDefLayerRotateAngleToValue) property to specify the default value for the RotateAngleToValue property, before adding the layer.

For instance:

• "0", specifies that the layer's value is always 0 no matter of the rotation angle of the layer.
• "value / 360 * 100", converts the angle to a percent
• "value / 360 / 24 / 60", converts the angle to a time value.

The RotateAngleToValue property supports the following keywords:

• value keyword indicates the layer's RotateAngle property

Also, this property supports all constants, operators and functions defined here.

The Value property indicates the value keyword in the following properties:

• ValueToRotateAngle, Specifies the expression to convert the value to rotating angle. The layer's RotateAngle property is the result of evaluating the ValueToRotateAngle expression, while the OnDrag property is exDoRotate or exDoRotamove. The RotateAngleToValue converts the current rotation angle to a value.
• ValueToOffsetX, Specifies the expression to convert the value to x-offset. The layer's OffsetX property is the result of evaluating the ValueToOffsetX expression, while the OnDrag property is exDoMove. The OffsetToValue converts the current offset to a value.
• ValueToOffsetY, Specifies the expression to convert the value to y-offset. The layer's OffsetY property is the result of evaluating the ValueToOffsetY expression, while the OnDrag property is exDoMove. The OffsetToValue converts the current offset to a value.

The following picture shows the rotation properties of the Layer, relative to the RotateCenterLayer layer:

Any of the following properties can be used to rotate the layer:

• DefaultRotateAngle, specifies the default angle to rotate the layer.
• RotateAngle, specifies the angle to rotate the layer.
• RotateAngleValid, validates / limits the rotation angle of the layer.
• Value and ValueToRotateAngle, specifies the expression to convert the value to rotating angle. The RotateAngleToValue converts the current rotation angle to a value.

The following properties can be used to specify a different rotation center:

• RotateCenterLayer, indicates the index of the layer the rotation is around.
• RotateCenterX, indicates the expression that determines the x-origin of the rotation point relative to the RotateCenterLayer layer.
• RotateCenterY, indicates the expression that determines the y-origin of the rotation point relative to the RotateCenterLayer layer. 

The following properties can be used to change the rotation center, while the layer's OnDrag property is exDoRotamove:

• RotamoveCenterX, specifies the x-position of the layer's center.
• RotamoveCenterY, specifies the y-position of the layer's center. 
• RotamoveOffsetX,  specifies the x-offset of the layer.
• RotamoveOffsetY, specifies the y-offset of the layer.