Deformation of a graphic object to emphasize effects of motion

• US 5,731,819 A
• Filed: 07/18/1995
• Issued: 03/24/1998
• Est. Priority Date: 07/18/1995
• Status: Expired due to Fees

• Current Assignee: Autodesk, Inc.
• Original Assignee: Softimage Co.
• Inventors: Verville, Vincent, Boucher, Yves, Gagne, Rejean
• Primary Examiner(s): Jankus, Almis R.
• Application Number:
  US08/503,522
• Time in Patent Office: 980 Days
• Field of Search: 395/133-139, 395/118, 395/119, 395/120, 395/123, 395/127, 395/141, 395/173-175, 345/433
• US Class Current: 345/647
• CPC Class Codes: G06T 17/20 Finite element generation, e.g. wire-frame surface description, tesselation

Abstract

A three-dimensional graphic object appearing in an animation is deformed to simulate the effects of motion on the object. A user can selectively apply a stretch, yield, or flex deformation effect to the control vertices of the object, to change the shape of the object as a function of any of a linear velocity, angular velocity, linear acceleration, or angular acceleration of the object. Various other parameters for each of these deformation effects can also be selected and set by the user, including a sensitivity to the motion in generating the deformation and a maximum deformation. The flex deformation can selectively be set to either a linear or curved profile, simulating the effect of friction applied by the environment on one or more surfaces of the object. The stretch deformation can selectively be set to either a constant or a free volume to simulate the effect of inertia, causing a body to elongate or shrink in the direction of the movement. The yield deformation can be set either a linear or curved profile, simulating the displacement of an object'"'"'s internal matter toward one end that occurs, relative to the direction of the object'"'"'s motion, i.e., causing one end to bulge. For each control vertex on the object, an effect offset is determined for each motion component and for each selected deformation effect. The sum of the effect offsets for the control vertex represents a total offset that is added to the original control vertex to determine a deformed control vertex. This step is repeated for all control vertices to produce the deformed object.

Claims

1. A method for deforming a graphic object, to simulate effects of motion, comprising the steps of:

(a) providing a motion vector for the graphic object that indicates its motion;

(b) providing a plurality of control vertices for the graphic object, said control vertices defining a shape of the graphic object;

(c) determining a plurality of offsets for the plurality of control vertices, as a function of the motion vector; and

(d) deforming the graphic object by applying the plurality of offsets to the plurality of control vertices, thereby changing a shape of the graphic object accordingly.

2. The method of claim 1, wherein the motion vector defines at least one of a linear velocity, a rotational velocity, a linear acceleration, and a rotational acceleration for the graphic object.

3. The method of claim 1, wherein the step of deforming comprises the step of applying at least one of a flex, a stretch, and a yield to the shape of the graphic object.

4. The method of claim 3, wherein the flex comprises one of a linear profile flex deformation and a curved profile flex deformation of the graphic object.

5. The method of claim 3, wherein the yield comprises one of a linear profile yield deformation and a curved profile yield deformation of the graphic object.

6. The method of claim 3, wherein the step of applying the stretch to the shape of the graphic object selectively maintains a volume of the graphic object constant, by compensating any change in the shape of the graphic object relative to a first axis by a proportional offsetting change in the shape of the graphic object relative to a second axis that is orthogonal to the first axis.

7. The method of claim 1, further comprising the step of enabling an operator to select at least one parameter that controls the deformation of the graphic object.

8. The method of claim 7, wherein said at least one parameter includes at least one of a maximum deformation, a deformation sensitivity, a type of deformation to be applied to the graphic object, and a motion vector for determining the deformation of the graphic object.

9. The method of claim 7, further comprising the step of tagging selected control vertices, said at least one parameter comprising an option to determine and to apply the offset only to the control vertices that are tagged.

10. The method of claim 7, said at least one parameter further comprising an option to preclude a deformation of the graphic object relative to at least one of a plurality of orthogonal axes.

11. The method of claim 1, wherein the motion vector is provided to deform a static graphic object.

12. A system for deforming a graphic object to simulate effects of motion, comprising:

(a) a central processor that executes machine instructions;

(b) a memory for storing the machine instructions to be executed by the central processor; and

(c) a monitor coupled to the central processor, for displaying the graphic object in accord with the machine instructions that are executed by the central processor, said machine instructions causing the central processor to;

(i) obtain a motion vector for the graphic object, said motion vector defining the translation or the rotation of the graphic object;

(ii) obtain a plurality of control vertices that define a shape of the graphic object;

(iii) determine offsets to be applied to the plurality of control vertices, as a function of the motion vector;

(iv) apply the offsets to the plurality of control vertices to produce a deformed graphic object; and

(v) display the deformed graphic object on the monitor.

13. The system of claim 12, wherein the motion vector defines at least one of a linear velocity, a rotational velocity, a linear acceleration, and a rotational acceleration for the graphic object.

14. The system of claim 12, wherein the offsets change a shape of the graphic object by applying at least one of a flex, a stretch, and a yield to the control vertices.

15. The system of claim 14, wherein the flex comprises one of a linear profile flex deformation and a curved profile flex deformation of the graphic object.

16. The system of claim 14, wherein the yield comprises one of a linear profile yield deformation and a curved profile yield deformation of the graphic object.

17. The system of claim 14, wherein when applying the stretch, a volume of the graphic object is selectively maintained constant by compensating any change in the shape of the graphic object relative to a first axis with a proportional offsetting change in the shape of the graphic object relative to a second axis that is orthogonal to the first axis.

18. The system of claim 12, wherein the machine instructions cause the central processor to enable an operator to select parameters that control the deformation of the graphic object.

19. The system of claim 18, wherein the parameters include at least one of a maximum deformation, a deformation sensitivity, a type of deformation to be applied to the graphic object, and a motion vector for determining the deformation of the graphic object.

20. The system of claim 18, wherein the machine instructions also cause the central processor to enable the operator to tag selected control vertices, said parameters further including an option to determine and to apply the offset only to the control vertices that are tagged.

21. The system of claim 18, wherein the parameters further include an option to enable the operator to selectively preclude a deformation of the graphic object relative to at least one of a plurality of orthogonal axes.

22. The system of claim 12, wherein the machine instructions also cause the central processor to enable the operator to selectively deform a static graphic object based on the motion vector.

23. An article of manufacture comprising:

(a) a nonvolatile memory storage device; and

(b) a plurality of machine instructions stored in the nonvolatile memory storage device, said plurality of machine instructions being adapted to cause a processor on which the plurality of machine instructions are executed to;

(i) obtain a motion vector for a graphic object that is to be deformed, deformation of the graphic object causing the graphic object to appear less stiff when the graphic object is translated or rotated;

(ii) obtain a plurality of control vertices that define a shape of the graphic object;

(iii) determine offsets to be applied to the plurality of control vertices, as a function of the motion vector;

(iv) apply the offsets to the plurality of control vertices to produce a deformed graphic object; and

(v) display the deformed graphic object on a monitor.

24. The article of manufacture of claim 23, wherein the motion vector defines at least one of a linear velocity, a rotational velocity, a linear acceleration, and a rotational acceleration for the graphic object.

25. The article of manufacture of claim 23, wherein the offsets change a shape of the graphic object by applying at least one of a flex, a stretch, and a yield to the control vertices.

26. The article of manufacture of claim 25, wherein the flex comprises one of a linear profile flex deformation and a curved profile flex deformation of the graphic object.

27. The article of manufacture of claim 25, wherein the yield comprises one of a linear profile yield deformation and a curved profile yield deformation of the graphic object.

28. The article of manufacture of claim 25, wherein when applying the stretch, a volume of the graphic object is selectively maintained constant by compensating any change in the shape of the graphic object relative to a first axis with a proportional offsetting change in the shape of the graphic object relative to a second axis that is orthogonal to the first axis.

29. The article of manufacture of claim 23, wherein the machine instructions cause the processor to enable an operator to select at least one parameter that controls the deformation of the graphic object.

30. The article of manufacture of claim 29, wherein said at least one parameter includes at least one of a maximum deformation, a deformation sensitivity, a type of deformation to be applied to the graphic object, and a motion vector for determining the deformation of the graphic object.

31. The article of manufacture of claim 29, wherein the machine instructions also cause the processor to enable the operator to tag selected control vertices, said at least one parameter including an option to determine and to apply the offset only to the control vertices that are tagged.

32. The article of manufacture of claim 29, wherein said at least one parameter includes an option to enable the operator to selectively preclude a deformation of the graphic object relative to at least one of a plurality of orthogonal axes.

33. The article of manufacture of claim 23, wherein the machine instructions also cause the processor to enable the operator to selectively deform a static graphic object based on the motion vector.