# Patent

## Title
Method and system for state-based control of objects

## Abstract

A method and system for state-based control of objects. A simulator controls data associated with a plurality of objects, the simulator including a first list of the plurality of objects and a data structure comprising data defining the plurality of objects. A state manager includes a plurality of states, wherein a state includes a second list of a subset of objects of the plurality of objects and determines a display appearance and a display action of the subset of objects. A plurality of software nodes are operable to perform associated operations on subsets of objects and to update data of the data structure for the subset of the objects.

## Background
FIELD OF INVENTION
The present invention relates to the field of computer-generated graphics. Specifically, embodiments of the present invention relate to a method and system for state-based control of objects.
BACKGROUND OF THE INVENTION
Recent technological advancements have led to the creation of a new interactive medium, the interactive video display system. Interactive video display systems allow real-time unencumbered human interactions with video displays. Natural physical motions by human users are captured by a computer vision system and used to drive visual effects. The computer vision system usually uses images captured by a video camera as input and has software processes that gather real-time information about people and other objects in the scene viewed by the camera. An output image is generated based on the human interaction as applied to an effects engine.
In order to customize the interaction with a user, artists can design different pieces of content, also referred to herein as “spots” or “video spots,” using the effects engine. A typical prior art effects engine is a large software component that is not easily changeable by the artist. Moreover, due to the large size of these effects engines, they are typically limited as to the number of objects that can be operated on by the effects engine.
For example, prior art effects engine often have difficulty providing position information, such as determining whether the object has entered a particular region or whether to trigger a collision between objects. Also, it may be difficult to dynamically generate objects. Furthermore, since there is no standard for particles or moving interactive objects, scripts created by an artist typically cannot be reused. This causes work of creating the scripts to be wasted or duplicated, reducing artist efficiency and increasing spot development costs. Moreover, due to the complexity of some desired effects and the limits of the effects engine, it may not be possible to create certain desired effects.
SUMMARY OF THE INVENTION
Various embodiments of the present invention, a method and system for state-based control of objects, are described herein. In one embodiment, the present invention provides a system for state-based control of objects including a simulator, a state manager, and a plurality of software nodes. A simulator controls data associated with a plurality of objects, the simulator including a first list of the plurality of objects and a data structure comprising data defining the plurality of objects. A state manager includes a plurality of states, wherein a state includes a second list of a subset of objects of the plurality of objects and determines a display appearance and a display action of the subset of objects. A plurality of software nodes are operable to perform associated operations on subsets of objects and to update data of the data structure for the subset of the objects. In one embodiment, the software nodes are operable to dynamically update the data structure.
In one embodiment, the simulator is operable to periodically generate a timing signal and wherein the software node is operable to perform an associated operation on the subset in response to receiving the time signal. In one embodiment, the software node is operable to perform an associated operation on the subset in response to receiving a signal indicating a change in an image.
In one embodiment, a state is associated with at least one the software node, wherein a state defines an effect. In one embodiment, the object is the minimal unit of an effect.
In one embodiment, the software node comprises a state change operation for changing a state of the subset of the objects. In other various embodiments, the software node may include an enabling operation for enabling a feature of objects of the subset, an object creation operation for creating at least one object, an object removal operation for removing at least one object, or a force operation for applying a force to objects of the subset. In another embodiment, the software node is operable to add new objects by updating the data structure to include data associated with the new objects.
In another embodiment, the present invention provides a method for state-based control of objects. Positions of a plurality of objects are updated by extracting data defining the plurality of objects from a data structure. A signal is received at at least one software node of a plurality of software nodes, wherein the software node is operable to perform an associated operation on a subset of the plurality of objects, wherein the subset is determined according to a state defining a display appearance and a display action of objects of the subset. A call for rendering data of the data structure is received. In one embodiment, the data of the data structure is updated for the subset of the objects. In one embodiment, the signal is a time signal. In another embodiment, the signal indicates a change in an image.



BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention:
FIG. 1A illustrates a projection interactive video display system, in accordance with an embodiment of the present invention.
FIG. 1B illustrates a self-contained interactive video display system, in accordance with an embodiment of the present invention.
FIG. 2 illustrates a system for rendering object data, in accordance with an embodiment of the present invention.
FIG. 3 illustrates a system for state-based control of objects, in accordance with an embodiment of the present invention.
FIG. 4 illustrates a process for state-based control of objects, in accordance with an embodiment of the present invention.



DETAILED DESCRIPTION
Reference will now be made in detail to various embodiments of the invention, a method and system for state-based control of objects, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it is understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be recognized by one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the invention.
Some portions of the detailed descriptions, which follow, are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, computer executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “defining” or “determining” or “identifying” or “performing” or “generating” or “receiving” or “updating” or “identifying” or the like, refer to the action and processes of an electronic system (e.g., object control system 300 of FIG. 3), or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the electronic device's registers and memories into other data similarly represented as physical quantities within the electronic device memories or registers or other such information storage, transmission or display devices.
Various embodiments of the present invention in the form of one or more exemplary embodiments will now be described. The described embodiments may be implemented on an interactive video display system including a vision system that captures and processes information relating to a scene. The processed information is used to generate certain visual effects that are then displayed to human users via an interactive display device. Human users are able to interact with such visual effects on a real-time basis.
FIG. 1A illustrates a projection interactive video display system 100 in accordance with an embodiment of the present invention. Projection interactive video display system 100 uses a camera 105, a projector 110 that projects an image 120 onto the interactive space 115 of surface 102, and a local computer (not shown) that takes as input the image of camera 105 and outputs a video image to projector 110.
The local computer processes the camera 105 input to discern on a pixel-by-pixel basis what portions of the volume in front of surface 102 (e.g., interactive space 115) are occupied by people (or moving objects) and what portions of surface 102 are background. The local computer may accomplish this by developing several evolving models of what the background is believed to look like, and then comparing its concepts of the background to what camera 105 is currently imaging. Alternatively, components of the local computer that process camera 105 input are collectively known as the vision system (e.g., vision system 210 of FIG. 2). Various embodiments of projection interactive video display system 100 and the vision system are described in co-pending U.S. patent application Ser. No. 10/160,217, filed on May 28, 2002, entitled “INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, and in co-pending U.S. patent application Ser. No. 10/974,044, filed on Oct. 25, 2004, entitled “METHOD AND SYSTEM FOR PROCESSING CAPTURED IMAGE INFORMATION IN AN INTERACTIVE VIDEO SYSTEM,” by Bell, and assigned to the assignee of the present application, both of which are herein incorporated by reference.
FIG. 1B illustrates a self-contained interactive video display system 150 in accordance with an embodiment of the present invention. Self-contained interactive video display system 150 displays an image onto display screen 155, and uses a camera (not shown) to detect people and objects in interactive space 160. A local computer, also referred to as the image system, takes as input the image of the camera and outputs a video image to display screen 155.
Various embodiments of self-contained interactive video display system 150 are described in co-pending U.S. patent application Ser. No. 10/946,263, filed on Sep. 20, 2004, entitled “SELF-CONTAINED INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell et al., and assigned to the assignee of the present application, co-pending U.S. patent application Ser. No. 10/946,084, filed on Sep. 20, 2004, entitled “SELF-CONTAINED INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, and co-pending U.S. patent application Ser. No. 10/946,414, filed on Sep. 20, 2004, entitled “INTERACTIVE VIDEO WINDOW DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, all of which are herein incorporated by reference. Furthermore, various embodiments of the vision system are described in co-pending U.S. patent application Ser. No. 10/160,217, filed on May 28, 2002, entitled “INTERACTIVE VIDEO DISPLAY SYSTEM,” by Bell, and assigned to the assignee of the present application, and in co-pending U.S. patent application Ser. No. 10/974,044, filed on Oct. 25, 2004, entitled “METHOD AND SYSTEM FOR PROCESSING CAPTURED IMAGE INFORMATION IN AN INTERACTIVE VIDEO SYSTEM,” by Bell, and assigned to the assignee of the present application, both of which are herein incorporated by reference.
Various embodiments of the present invention are described herein. According to one embodiment of the interactive video display system (e.g., projection interactive video display system 100 of FIG. 1A), there is an input image from a monochrome camera (e.g., camera 105 of FIG. 1A) and a computer vision system that is able to separate foreground objects of interest (e.g., people) from the background of the input image in real time so that the location and outline of the foreground objects can serve as input to an interactive application.
The camera input image is an image representing a real world scene viewed by the camera. This real world scene contains a static background of unknown brightness and appearance as well as various foreground objects that are able to move, such as, people and objects held or moved by people. The camera input image may be manipulated or cropped so that the area viewed by the camera corresponds to the boundaries of a display.
FIG. 2 illustrates a system 200 for rendering object data, in accordance with an embodiment of the present invention. System 200 includes vision system 210, object management system 300, and rendering module 220. Vision system 210 is operable to outputs a foreground/background distinction image that corresponds to the camera input image. Each pixel in this image is capable of assuming one of two values: one value for foreground and another value for background. This pixel's value represents whether the vision system determines the pixel with the same position in the camera input image is foreground or background. In one exemplary embodiment, the foreground/background distinction image is an 8-bit grayscale image, with a pixel value of “0” for background and a pixel value of “255” for foreground.
In one embodiment, the foreground/background distinction image is used to generate a gradient image. The gradient image includes the foreground as defined by the foreground/background distinction image with force vectors perpendicular to the foreground objects representing the forces exerted by the foreground objects. In one embodiment, the gradient image is used as the input to a software node (e.g., of software nodes 330 of FIG. 3).
Object management system 300 is operable to control and manage the data associated with the appearance of objects. FIG. 3 illustrates object management system 300 for state-based control of objects, in accordance with an embodiment of the present invention. Object management system 300 includes simulator 310, state manager 320 and software nodes 330. Objects are instances of data that can be changed by effects, thus changing the on-screen appearance of the object. For instance, an effect may change the screen location, speed, and acceleration of the object. In one embodiment, the object is the minimal unit of an effect.
Simulator 310 is operable to control data associated with a plurality of objects, and includes object list 312 and data layout 314 to control and manage the data. Object list 312 includes a list of all objects controlled by simulator 310. Data layout 314 is a data structure including the data that defines the objects included in object list 312. By maintaining data layout 314 separate from object list 312, it is possible to dynamically update data layout 314 without modifying object list 312, improving processing speed.
In one embodiment, simulator 310 includes time signal 316. Time signal 316 is a periodic time signal associated with a clock cycle. It should be appreciated that simulator 310 may generate time signal 316 or receive time signal 316 from an external source. Time signal 316 is used for directing certain software nodes to execute.
State manager 320 includes a plurality of states 322a-n, wherein a state is a list of a subset of the objects of object list 312 (e.g., object subset lists 324a-n). It should be appreciated that state manager 320 can include any number of states. A state determines a display appearance and a display action of the subset of objects. In one embodiment, a state includes a user-defined list. A state determines which objects are executed by a particular software node or a group of software nodes. In other words, a state defines an effect. A user selects which objects are included in a state and which software node or nodes are executed on the selected subset of objects.
As described above, in one embodiment, a state includes one associated software node. By associating a state with a single software node, processing time for executing the software node is improved, because the associated subset of objects is already included in the state.
Software nodes 330 include any number of software nodes 330a-n for performing associated operations on a subset of objects (e.g., object subset lists 332a-n). In one embodiment, the object subset list for a corresponding software node is received from state manager 320. For example, a software node assign properties to an object, create or delete an object, enable enhanced features of an object, apply forces to an object, select an object, change the state of an object, or many other operations. The following are lists of exemplary software nodes that can be used in various embodiments of the present invention.
Assign software nodes—assign properties to objects:

    
    
        Assign mass software node—control mass of the object;
        Assign position software node—control position of the object;
        Assign renderable software node—control rendering of the object;
        Assign rotation software node—control rotation of the object;
        Assign shape software node—control shape of the object;
        Assign state software node—control state of the object; and
        Assign velocity software node—control velocity of the object.
    
    


Emit software nodes—create or delete objects:

    
    
        Delete software node—delete an object;
        Emit software node—create an object;
        Emit copy software node—create new object by copying positions and velocities of old objects;
        Emit pattern software node—create new objects in a specific pattern;
        Emit pointlist software node—create new objects at a list of positions;
        Emit rate software node—create new objects at a particular rate;
        Emit sprinkle software node—create new objects based on image input; and
        Reset software node—causes simulation to reset.
    
    


Enable software nodes—enable optional object features:

    
    
        Enable jello software node—interaction makes object distort;
        Enable render software node—render objects as a three-dimensional renderable nodes that use an openGL environment; and
        Enable shape software node—enable objects to be assigned shapes, so that they can later be used for detecting and controlling interactions such as collisions.
    
    


Force software nodes—apply forces to objects:

    
    
        Force friction software node—slows down movement of an object;
        Force gradient software node—move object according to a gradient image;
        Force gravity software node—move object toward or away from a point;
        Force input software node—apply a force to an object;
        Force repulsion software node—make all objects push away from each other;
        Force roll software node—rotate an object; and
        Force wind software node—all objects move in a selected direction at a selected speed.
    
    


Selection software nodes—selects certain types of objects:

    
    
        Select age software node—select objects greater than a certain age;
        Select collision software node—outputs reported collisions;
        Select count software node—provide a count of all objects;
        Select image software node—reads from an image at each object position;
        Select join software node—outputs a combination of two object inputs;
        Select pressure software node—indicates whether an object was interacted with; and
        Select rotation software node—output a list of objects above a certain rotation.
    
    


State software nodes—declare a state that can contain objects within it or can direct objects to another state.
A user is able to define states that include subsets of objects, and have selected software nodes applied to the subsets to create a desired spot or presentation. For example, a state may be defined for deleting objects that have reached a certain age. The select age software node is used to select these objects, and the delete object software node is applied to the selected objects, thereby deleting them. Many different combinations of software nodes can be used to define many different states.
Software nodes may be executed in response to receiving signals. In one embodiment, a software node is operable to perform an associated operation in response to receiving time signal 316. For example, the selection software nodes may be executed periodically according to time signal 316. In another embodiment, a software node is operable to perform an associated operation on in response to receiving a signal indicating a change in an image. In another embodiment, a software node is operable to perform an associated operation in response to receiving a signal indicating a change in state of an object.
Moreover, it should be appreciated that the software nodes may include additional user-defined attributes. For example, the assign shape software node allows a user to define a shape. In another example, the emit pattern software node allows a user to select or define a pattern for creating new objects.
A software node is also operable to update data for associated objects. For instance, software node 330a of FIG. 3 is operable to update the data of data layout 314 for objects in object subset list 332a. In one embodiment, the software nodes are operable to update the data of data layout 314 dynamically. In another embodiment, a software node is operable to update the data of data layout 314 to include new objects.
With reference again to FIG. 2, rendering module 220 is shown. The data for objects that is stored in data layout 314 of FIG. 3 is accessible for rendering. In one embodiment, the data is rendered using a projection display (e.g., interactive video display system 100 of FIG. 1A). In another embodiment, the data is rendered using a flat-panel display (e.g., self-contained interactive video display system 150 of FIG. 1B). In another embodiment, the data can be rendered audibly. In another embodiment, the data can be rendered using other types of electronic devices (e.g., lights, automatic doors, etc.) It should be appreciated that the data can be rendered by rendering module 220 in many different types of ways, and is not intended to be limited to the described embodiments.
FIG. 4 illustrates a computer-controlled process 400 for state-based control of objects, in accordance with an embodiment of the present invention. In one embodiment, process 400 is carried out by processors and electrical components (e.g., object management system 300 of FIG. 3) under the control of computer readable and computer executable instructions, such as the described vision system. Although specific steps are disclosed in process 400, such steps are exemplary. That is, the embodiments of the present invention are well suited to performing various other steps or variations of the steps recited in FIG. 4. For purposes of simplicity, process 400 describes the steps associated with one clock cycle of an object management system.
At step 410 of process 400, positions of a plurality of objects are updated. In one embodiment, the positions are updated by extracting data defining the plurality of objects from a data structure (e.g., data layout 314 of FIG. 3). In one embodiment, the velocities of the plurality of objects is also updated. In one embodiment, simulator 300 is operable to perform a solver operation for determining the positions and velocities of all objects. For example, the solver may calculate the force exerted on an object according to a force software node. Other examples include the solver calculating the velocity from the assign velocity software node, the solver calculating the position from the assign position software node, or identifying collisions between objects according to the select collision software node.
At step 420 a signal is received for directing at least one software node to perform associated operations on a subset of the objects. The subset is determined according to a state defining a display appearance and a display action of objects of the subset. In one embodiment, the state is controlled by state manager 320 of FIG. 3. In one embodiment, the signal is a time signal. In another embodiment, the signal indicates a change in an image. In another embodiment, the signal indicates a change in state of an object or subset of objects. In one embodiment, a state is associated with at least one the software node, wherein a state defines an effect. In one embodiment, the object is the minimal unit of an effect.
At step 430, the software node is executed in response to the signal. Depending on the type of signal (e.g., time signal, image change signal, or state change signal), certain software nodes execute. As described above, in one embodiment, a software node is operable to perform an associated operation in response to receiving time signal 316 of FIG. 3. For example, the selection software nodes may be executed periodically according to time signal 316. In another embodiment, a software node is operable to perform an associated operation on in response to receiving a signal indicating a change in an image. In another embodiment, a software node is operable to perform an associated operation in response to receiving a signal indicating a change in state of an object. It should be appreciated that steps 420 and 430 may be performed in any order relative to steps 410, 440 and 450. Moreover, it should be appreciated that steps 420 and 430 may be performed multiple times during process 400. For example, steps 420 and 430 may be performed for a time signal early in process 400, and then performed for an image change signal later in process 400.
In one embodiment, the software node comprises a state change operation for changing a state of the subset of the objects. In other various embodiments, the software node may include an enabling operation for enabling a feature of objects of the subset, an object creation operation for creating at least one object, an object removal operation for removing at least one object, or a force operation for applying a force to objects of the subset. In another embodiment, the software node is operable to add new objects by updating the data structure to include data associated with the new objects.
At step 440, a call for rendering data of the data structure is received. As described above, the data for objects that is stored in data layout 314 of FIG. 3 is accessible for rendering, e.g., by rendering module 220 of FIG. 2. In one embodiment, the data is rendered using a projection display (e.g., interactive video display system 100 of FIG. 1A). In another embodiment, the data is rendered using a flat-panel display (e.g., self-contained interactive video display system 150 of FIG. 1B). In another embodiment, the data can be rendered audibly. In another embodiment, the data can be rendered using other types of electronic devices (e.g., lights, automatic doors, etc.) It should be appreciated that the data can be rendered by in many different types of ways, and is not intended to be limited to the described embodiments.
At step 450, data of the data structure for the subset of the objects is updated. In one embodiment, the data of the data structure is updated by the software nodes. In one embodiment, the software nodes are operable to dynamically update the data structure. The software nodes also may be operable to add new objects by updating the data structure to include data associated with the new objects.
In an exemplary implementation, the present invention is implemented using software in the form of control logic, in either an integrated or a modular manner. Alternatively, hardware or a combination of software and hardware can also be used to implement the present invention. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will know of other ways and/or methods to implement the present invention.
Various embodiments of the present invention, a method and system for state-based control of objects, are described herein. In one embodiment, the present invention provides a for state-based control of objects, allowing users to define states as including a subset of objects and associated with specified software nodes. By providing a framework in which the appearance of objects is controlled according to a state, a user designing a spot is provided with improved functionality. Moreover, by storing the data in a separate data structure, performance of the system is improved, increasing the number of objects that may be controlled and improving the appearance of the objects.
It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference for all purposes in their entirety.
Various embodiments of the invention, a method and system for state-based control of objects, are thus described. While the present invention has been described in particular embodiments, it should be appreciated that the invention should not be construed as limited by such embodiments, but rather construed according to the below claims.

## Claims

1. A method for state-based control of objects in an interactive video display system including a camera based interface, the method comprising:
storing an object list comprising a plurality of objects;
storing a data structure comprising properties associated with respective objects, wherein the properties indicate display actions or display appearances of respective objects;
defining a state to include a subset of objects of the object list that are selected by user input;
associating a first software node with the state;
associating a second software node with the state;
in response to receiving a first signal indicating execution of the first software node, executing the first software node on the subset of objects of the state to modify one or more properties of the subset of objects in the state stored in the data structure, wherein the first signal is representative of a first user interaction with an interactive video display system;
in response to receiving a second signal indicating execution of the second software node, executing the second software node on the subset of objects of the state to modify one or more properties of the subset of objects in the state stored in the data structure, wherein the second signal is representative of a second user interaction with the interactive video display system; and
rendering the objects that have been modified by the software nodes on a display device of the interactive video display system.

2. The method of claim 1, further comprising executing a third software node to create a new object based on a property of another object.

3. The method of claim 1, further comprising executing a third software node to delete an object based on a property of another object.

4. The method of claim 1, wherein the first software node calculates a force to be applied to each of the objects indicated by the state based at least in part on the first user interaction with the interactive video display system.

5. The method of claim 1, wherein the first software node calculates an alteration of position or velocity to be applied to each of the objects indicated by the state based at least in part on the first user interaction with the interactive video display system.

6. The method of claim 1, wherein the first signal is further representative of a timing signal that controls the execution of the first software node.

7. A computerized method for controlling objects in an interactive video display system, the method comprising:
storing properties of a plurality of objects in memory, the plurality of objects appearing on an interactive video display;
receiving user interaction data indicating one or more interactions of a user with the interactive video display;
associating a first subset of the plurality of objects with a first software node based at least in part on the user interaction data, wherein the first subset comprises two or more objects;
associating a second subset of the plurality of objects with a second software node based at least in part on the user interaction data, wherein the second subset comprises two or more objects, including at least one object that is in the first subset of objects;
executing the first software node on each of the objects in the first subset of objects at a computing device, wherein execution of the first software node changes at least a first property of each of the objects in the first subset of objects;
executing the second software node on each of the objects in the second subset of objects at a computing device, wherein execution of the second software node changes at least a second property of each of the objects in the second subset of objects; and
initiating display of the subset of objects on the interactive video display.

8. The method of claim 7, wherein the at least a first property defines a display appearance or a display action.

9. The method of claim 7, wherein the first subset of the plurality of objects is selected based in part on a property of the objects.

10. The method of claim 7, further comprising executing a third software node to create a new object based on a property of an object in the first subset of objects.

11. The method of claim 7, further comprising executing a third software node to remove an object from the first subset of objects based on a property of the object.

12. A computing system for managing objects in an interactive video display system including an imaging device, the system comprising:
a non-transitory computer readable medium configured to store properties associated with respective objects of a plurality of objects, wherein at least some of the properties associated with the respective objects indicate appearance characteristics of the respective objects;
an interface configured to receive user interaction data from an imaging device, the user interaction data indicating user interactions with the a video display; and
a processor configured to:
associate a first subset of the plurality of objects with a first state based on the user interaction data, wherein the first subset comprises two or more objects;
associate a second subset of the plurality of objects with a second state based on the user interaction data, wherein the second subset comprises two or more objects, including at least one of the objects of the first subset;
execute a first software node on each of the plurality of objects associated with the first state, wherein execution of the first software node changes a first property of the objects in the first subset; and
execute a second software node on each of the plurality of objects associated with the second state, wherein execution of the second software node changes a second property of the objects in the second subset.

13. The system of claim 12, wherein the processor is further configured to:
associate the first software node with the first state, and
execute the first software node on objects associated with the first state.

14. The system of claim 12, wherein the objects in the first subset of the plurality of objects are associated with the first state based at least in part on the user interaction data.

15. The system of claim 13, wherein executing the first software node on the first subset of the plurality of objects modifies a property of the respective objects based at least in part on the user interaction data.

16. The system of claim 13, wherein executing the first software node performs one or more of assigning a property to the objects associated with the first state, applying a force to the objects associated with the first state, deleting the objects associated with the first state, changing the state associated with the objects associated with the first state, and enabling a feature of the objects associated with the first state.

17. The system of claim 12, wherein the processor is further configured to:
initiate display of at least one of the objects associated with the first state on the video display.

18. A non-transitory tangible computer readable storage medium having software instructions stored thereon, the software instructions readable by a computing system comprising one or more computing devices, wherein the software instructions are executable on the computing system in order to cause the computing system to perform operations comprising:
storing properties of respective objects of a plurality of objects in a storage device, wherein the properties indicate respective display appearances or display actions of the respective objects;
receiving input data from a camera indicative of a first user interaction and a second user interaction with a video display;
generating a first list of two or more objects in response to the first user interaction;
generating a second list of two or more objects in response to the second user interaction, wherein the first and second lists each include a first object;
executing a first software node on the objects indicated by the first list to modify a respective first property of the objects;
executing a second software node on the objects indicated by the second list to modify a respective second property of the objects; and
initiating display of the modified objects on the video display.

19. The non-transitory tangible computer readable storage medium of claim 18, wherein the first list corresponds to a display effect of the objects indicated by the first list.

20. The non-transitory tangible computer readable storage medium of claim 19, wherein the operations further comprise:
associating the first software node with the first list of objects; and
executing the first software node only on the objects indicated by the first list of objects.