Alan Borning and Bjorn N. Freeman-Benson. Ultraviolet: A constraint satisfaction algorithm for interactive graphics. Constraints, 3(1):932, 1998.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....quite different from the goal of interactive back end computation. When executing a constraint program, the constraint run time system searches for a solution that best satisfies all of the constraints, typically through a search technique or by the application of cycle specific constraint solvers [2]. In contrast, for interactive tools, it is usually quite obvious how to achieve the end result, and in fact there are often a great many possible ways. In order to remain interactive, the back end must select the particular execution that satisfies the requirements for interactivity. The Java ....

.... wd.register(updatescroll) netpix = mint(mmul(tsc, wavdur) # Net scrollable pixel region 115 def doscroll( args) # Translate Tk scroll events # into changing xv vw = string.atof(args[1] 120 if args[0] moveto : loc = vw pix = int(loc netpix.force( else: if args[2] = pages : 125 pix = xv.force( int(vw wd.force( else: pix = xv.force( int(vw wd.force( 0.20) if pix 0: 130 pix = 0 if pix wd.force( netpix.force( pix=netpix.force( wd.force( 135 xv.change(pix) tscroll = tk.Scrollbar(root, orient= horizontal , command=doscroll) ....

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A. Borning and B. Freeman-Benson. Ultraviolet: A constraint satisfaction algorithm for interactive graphics. CONSTRAINTS: An International Journal, Special Issue on Constraints, Graphics, and Visualization, 3(1):9--32, April 1998.

....objects are to be placed in a group, and hence is restrictive. The interactive grouping mechanisms presented here are based on the use of constraints to simplify the manipulation of objects in a scene. Several researchers have presented different forms of 2D constraint based systems (see e.g. [2,4,6,11,15,21]) For an overview of constraint solvers see [8] Several constraint based systems have been presented for 3D modeling (see e.g. 1,3,5,9,10,14] While these systems use the constraints to afford direct object manipulation, the manipulation of groups is not simplified similarly. e.g. while a ....

A. Borning, B. Freeman, Ultraviolet: A Constraint Satisfaction Algorithm for Interactive Graphics, Constraints: An International Journal, 3, 1998, 1-26.

....in 3D much simpler. VRIC, Virtual Reality International Conference, Lava Virtual 2001, May 16 18 1.1 Previous Work For 2D object manipulation various forms of constraint systems have been introduced. For recent work on interactive constraint satisfaction and references to previous work see [4][19] Previous work on 3D object manipulation can be classified into two categories: those that use 2D and those that use 3D input devices. The simplest solution for a 2D input device is to decompose the manipulation task into positioning and orientation. Unfortunately, there is no intuitive ....

....need only be checked between that moving object, and the rest of the objects in the scene. If no collisions are found, then the constraint was successful. In addition, a binding area cannot be bound to an offer area of the same object: an object cannot be constrained to itself. In Borning s [4] terms, our system implements locally predicate better constraints. To constrain an object, we attempt to satisfy all of its binding areas. For each binding area of an object, we search through the scene to find potential satisfying offer areas. Semantics restrict the offer areas that a binding ....

Borning, A., Freeman, B., Ultraviolet: A Constraint Satisfaction Algorithm for Interactive Graphics, Constraints: An International Journal, 3, 1-26, 1998.

....after rotation and translation the binding polygon is not completely enclosed by the offer polygon, then the binding area is not constrained to the offer area. In addition, a binding area cannot be bound to an offer area of the same object: an object cannot be constrained to itself. In Borning s [4] terms, our system implements locally predicatebetter constraints. To constrain an object, we attempt to satisfy all of its binding areas. For each binding area of an object, we search through the scene to find potential satisfying offer areas. Semantics restrict the offer areas that a binding ....

Borning, A., Freeman, B., Ultraviolet: A Constraint Satisfaction Algorithm for Interactive Graphics, Constraints: An International Journal, 3, 1-26, 1998.

....[122] Such a system has been used in graphic editors, for the error correction in visual language parsing, for graph layout, and for interactive document layout on the Internet. Another constraint solving algorithms, especially designed for interactive graphical applications, is Ultraviolet [23]. Constraints have also been used to add useful features and efficiency to graph drawing algorithms [171] and to generic visualization and animation tools [170] A graphical interface using constraint based techniques has been developed to solve the assem13 bly problem (that is, the spatial ....

A. Borning and B. Freeman-Benson. Ultraviolet: a constraint satisfaction algorithm for interactive graphics. CONSTRAINTS: An International Journal, 3(1), 1998.

....the floor. This concept of constraints makes manipulating objects in 3D with 2D devices much simpler. Previous Work For 2D object manipulation various forms of constraint systems have been introduced. For recent work on interactive constraint satisfaction and references to previous work see [4][19] Previous work on 3D object manipulation can be classified into two categories: those that use 2D and those that use 3D input devices. The simplest solution for a 2D input device is to decompose the manipulation task into positioning and orientation. Unfortunately, there is no intuitive ....

....after rotation and translation the binding polygon is not completely enclosed by the offer polygon, then the binding area is not constrained to the offer area. In addition, a binding area cannot be bound to an offer area of the same object: an object cannot be constrained to itself. In Borning s [4] terms, our system implements locally predicate better constraints. To constrain an object, we attempt to satisfy all of its binding areas. For each binding area of an object, we search through the scene to find potential satisfying offer areas. Semantics restrict the offer areas that a binding ....

Borning, A., Freeman, B., Ultraviolet: A Constraint Satisfaction Algorithm for Interactive Graphics, Constraints: An International Journal, 3, 1-26, 1998.

....the floor. This concept of constraints makes manipulating objects in 3D with 2D devices much simpler. 1.1 Previous Work For 2D object manipulation various forms of constraint systems have been introduced. For recent work on interactive constraint satisfaction and references to previous work see [4][19] Previous work on 3D object manipulation can be classified into two categories: those that use 2D and those that use 3D input devices. The simplest solution for a 2D input device is to decompose the manipulation task into positioning and orientation. Unfortunately, there is no intuitive ....

....If after rotation and translation the binding polygon is not completely enclosed by the offer polygon, then the binding area is not bound to the offer area. In addition, a binding area cannot be bound to an offer area of the same object: an object cannot be constrained to itself. In Borning s [4] terms our system implements locallypredicate better constraints. Dual constraints are defined as points instead of areas (like binding and offer areas) To satisfy a dual constraint between two objects D1 and D2, we match up their dual points and rotate their orientation vectors in opposing ....

Borning, A., Freeman, B., Ultraviolet: A Constraint Satisfaction Algorithm for Interactive Graphics, Constraints: An International Journal, 3, 1-26, 1998.

....should be available to point out conflicts and to guide the user in resolving them. The CSPs used to define animations exhibit many characteristics as listed below, which restrict the choice of applicable solution methods. All but the last two are common in interactive graphical systems (Borning et al. 1998). Non functional constraints: if all but one variables of a constraint are instantiated, there can be more than a single possible value chosen for the remaining variable in such a way that the constraint is satisfied. Multi way constraints: there is no general input output role assigned to ....

Borning, A., Freeman-Benson, B. (1998) Ultraviolet: A constraint satisfaction algorithm for interactive graphics, Constraints , Vol. 3., 1. pp. 9-32.

....need not exploit constraint solving to be of value. These special relationships, by necessity, must be disconnected from the rest of the constraint graph, and the technique can be seen as simply a very restricted domain specific sub solver, similar to the sub solvers used by Ultraviolet [13] or DETAIL [79] 3 Interactive constraint solvers are often split into a planning, or compilation, stage and an execution stage. During planning, the solver pre computes all state that will remain fixed throughout a class of executions. These restrictions permit the system to be more efficient ....

....recognizing the similarities among the approaches, and considering novel combinations of various systems exposes many areas for future work. Extensible solvers are a useful and flexible mechanism for exploiting domain dependent optimizations while retaining generality. In particular, Ultraviolet [13] provides a useful framework for embedding solvers, but does not have an integrated, fully general linear equality and inequality sub solver. Physically based systems such as the spring layout of GLIDE [122] and differential methods of Briar [59, 57] demonstrate advantages of using ....

Alan Borning and Bjorn Freeman-Benson. Ultraviolet: A constraint satisfaction algorithm for interactive graphics. Constraints: An International Jounal, 3:1--26, 1998.

....stacks of integers. It can be extended for other data structures and other predefined and complex types. Finally, the third part consists of an implementation of the algorithm of satisfaction which is based on a combination of the algorithms of Arc consistency [11] SkyBlue [19] and Ultraviolet [7]. This algorithm uses ideas of division in regions, satisfaction in pares, and reduction of the domain of constrained variables by discarding values, which are modified and adapted to our library. Constraints for Non Predefined Data Types 72 7. Conclusion This paper has described an object ....

Borning, A., Freeman-Benson, B. "Ultraviolet : A Constraint Satisfaction Algorithm for interactive Graphics", Technical Report, University of Washington, Dept of Computer Science and Engineering.

....mechanisms should be available to point out conflicts and to guide the user in resolving them. The CSPs used to define animations exhibit many characteristics as listed below, which restrict the choice of applicable solution methods. All but the last two are common in interactive graphical systems (Borning et al. 1998). ffl Non functional constraints: if all but one variables of a constraint are instantiated, there can be more than a single possible value chosen for the remaining variable in such a way that the constraint is satisfied. ffl Multi way constraints: there is no general input output role assigned ....

Borning, A., Freeman-Benson, B. (1998) Ultraviolet: A constraint satisfaction algorithm for interactive graphics, Constraints , Vol. 3., 1. pp. 9-32.

....system is the engine that satisfies the relationship. These special relationships, by necessity, must be disconnected from the rest of the constraint graph, and the technique can be seen as simply a very restricted domain specific sub solver, similar to the sub solvers used by Ultraviolet [BFB98] or detail [HMT 94] 6 6 In contrast, the Juno systems [Nel85, HN94] take this approach to an extreme and permit the user to specify Interactive satisfaction algorithms Greg J. Badros Green QuickPlan DeltaStar over flat solvers SkyBlue to walk bounds) UltraViolet Cassowary ....

....3.2.3 Extensible local propagation solvers There are three main limitations of DeltaBlue: 1) it can handle only functional constraints (e.g. it cannot manage inequalities) 2) it cannot solve cyclic constraint graphs; and 3) all methods must have exactly one output variable. The Indigo solver [BFB98] relaxes the first restriction by propagating bounds on value assignments instead of specific values the bindings Indigo makes to variables are intervals. This generalization requires the solver to fire multiple interval tightening methods instead of just a single method performing a value ....

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Alan Borning and Bjorn Freeman-Benson. Ultraviolet: A constraint satisfaction algorithm for interactive graphics. Constraints: An International Jounal, 3:1--26, 1998.

....limit constraint hierarchies to being statically defined, that is, they cannot dynamically change hierarchies after compilation. UltraViolet is a hybrid algorithm that divides constraint hierarchies into subgraphs based on graph topology and constraint types and then invokes appropriate subsolvers [8, 10]. Menezes s incremental hierarchical constraint solver satisfies constraint hierarchies over finite domains using a search technique [60] 7.5 Other Over Constrained Systems Hattori proposed executable constraints [31] Each executable constraint is a macro defined by an end user of a GUI system, ....

Borning, A. and B. Freeman-Benson, "UltraViolet: A Constraint Satisfaction Algorithm for Interactive Graphics," CONSTRAINTS: An International Journal, To appear. BIBLIOGRAPHY 106

....that can be executed repeatedly to re solve the constraints with different input parameters. We can view this as a kind of partial evaluation of the constraint solving algorithm. This has long been done for local propagation solvers (e.g. 1] and more recently for simultaneous linear equations [4] and for acyclic sets of inequality constraints [2] However, there have not been any systems that can compile plans for systems of constraints including a cyclic set of simultaneous equalities and inequalities. That lack is addressed here. The original motivation for this work was constraint ....

Alan Borning and Bjorn Freeman-Benson. Ultraviolet: A constraint satisfaction algorithm for interactive graphics. Constraints: An International Journal, 3(1):9-32, April 1998.

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Alan Borning and Bjorn N. Freeman-Benson. Ultraviolet: A constraint satisfaction algorithm for interactive graphics. Constraints, 3(1):932, 1998.

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A. Borning and B. Freeman-Benson. Ultraviolet: A constraint satisfaction algorithm for interactive graphics. Constraints: An International Journal, 3(1):9--32, 1998.

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