KR20100138591A - Motion retargetting system and its using method based on character's physical properties - Google Patents

Abstract

PURPOSE: A motion re-targeting system based on character's physical properties and a method for using the system are provided to convert motion of a human body into physical properties of a character, thereby generating motion data of high quality. CONSTITUTION: A motion data unit stores motion data. A character parameter data unit(220) stores physical information of a character to which the motion data is applied. A motion deformation engine unit(230) uses the motion data and the physical information of the character to produce deformed motion data.

Description

Motion retargetting system and Its using method based on character's physical properties}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion retargeting system and a method for retargeting a motion. After generating motion data by adding information about physical properties of a human body to motion capture data, the physical information of the character is generated. The present invention relates to a technique for generating motion data of higher quality by using.

Recently, with the development of computer graphics technology and virtual reality technology, a case of applying a motion of a real person or a character to various contents has been spreading.

In this case, virtual reality means that humans can interact with the five senses in cyberspace built using computers to indirectly experience situations that cannot be directly experienced by activities in the real world or by spatial and physical constraints. It is a new paradigm of information activity.

Such virtual reality technology has been tried in various fields, for example, multimedia contents, electronic games, movies, various education and training systems and the like. As the film and game industries develop and three-dimensional modeling, rendering, and animation techniques are introduced, interest in technologies that can generate more natural motions is focused.

Recently, in order to obtain natural motion data quickly and realistically, motion capture technology has been introduced that captures human motion as it is, inputs numerical motion data into a computer, and moves a character using the motion data.

In general, motion capture technique is one of motion generation techniques that capture the movement of the character of the real world with a special camera and apply it to a virtual character on the computer. Unlike other motion generation techniques, the motion of the character of the real world is as it is. There is a big advantage to being able to reproduce.

Motion capture refers to recording the movement of an object such as a person, animal, creature, or machine in a form usable by a computer. The advantage of the motion capture system is the introduction of realistic expressions of humans and animals, large scales, and a lot of economic burden, which are difficult to express with the existing key frame method. Increasingly, the frequency of use is increasing, including movies, TV, commercials, documentaries, and music videos.

As such, motion capture data or motion data is captured by capturing real human motions and used in computer graphics, and motion retargeting technology that applies motion capture data to a character is used for animation production. It is actively utilized.

However, although motion capture data is excellent in the application of rendering technology for obtaining high quality animation images in character animation or game production, the reality of lacking a part for expressing motions in accordance with the quality of animation. In general, there is a problem in that it is not easy to apply motion capture data to fit the unique characteristics of the character.

The important issues in motion capture technology are weight distribution, weight, and exaggeration of exaggerated motion. According to the conventional technology, actors expressing human body motion can exaggerate motion like cartoon characters. There was no problem, and when the motion capture data obtained from the human body was applied to a character with different body proportions, there was a limit in the expression of the weight.

Conventional motion retargeting method is to apply the rotation value of the data to the joints of the character as it is, to transform to meet the given conditions using inverse kinematics (IK) according to the relationship with the outside. In other words, it is possible to obtain a new rotation value of the joint using inverse kinematics (IK) so that the foot is not slipped from the floor in the walking motion and this is satisfied.

This method modifies the motion of the joints to fit the constraints arbitrarily, resulting in a partly unnatural motion and the need for motion correction to partially filter or blend the motion. There was a problem that the targeting method was complicated and the correction procedure was required.

Therefore, in the motion retargeting method, a motion retargeting method for guaranteeing the expression of the weight of a character, natural movement, etc. is required even when motion capture data obtained from the human body is applied to a character having different body proportions, and also a motion retargeting method. There is a need for a simple manufacturing method that does not require a separate complicated manufacturing procedure such as the correction procedure.

The present invention relates to a motion retargeting system and a method of using the same, which are designed to solve the above-described problems of the prior art, and include information on a physical attribute of a human body to motion capture data, and a character and The purpose is to generate high quality motion data close to reality in consideration of the influence of external factors to which a character is applied.

In addition, the present invention is to solve the difficulty and complexity of the conventional motion retargeting method to create high-quality motion data more easily and conveniently to facilitate animation production.

The technical objects to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical subjects which are not mentioned can be clearly understood by those skilled in the art from the description of the present invention .

According to an embodiment of the present invention for achieving the above object, a motion data unit for storing motion data, a character parameter data unit for storing physical information of the character to apply the motion data and the motion data of the character It consists of a motion retargeting system including a motion deformation engine to calculate the modified motion data using physical information.

The present invention includes a motion data unit for storing motion data.

In the present invention, the motion data consists of adding information of the height, weight, position of the joint, length of the joint, center of gravity of the joint and moment of inertia of the joint to the motion capture data obtained by digitizing the motion of the human body. Includes as a feature.

The motion data may be made by adding physical information of the human body, that is, weight, height, length of a joint, a center of gravity of a joint, and moment of inertia of the joint to motion capture data obtained by digitizing the motion of the human body. That is, when motion capture data is reinterpreted and decomposed into physical quantities such as the mass of the joint, the length of the joint, the center of mass, and the moment of inertia, the motion capture data is applied to the character. It is possible to generate motion data to which the properties of the character are applied.

The motion data may include a shape portion constituting the joint information of the human body and an operation portion constituting the rotation of the joint, and may be stored as a file having an extension of BVH or HTR format.

i) The shape part is the basic shape information of the main joints of the human body and contains basic posture information of the T-shape, and the joint information is described as a position value relative to the parent joint, and the parent joint may have multiple child joints. However, a child joint can have only one parent joint. Here, the parent joint refers to a joint near the torso, that is, a joint such as a shoulder, pelvis, and spine, and the child joint refers to a joint far from the torso from the parent joint, that is, if the parent joint is a shoulder joint, the child joint This is the elbow, wrist, and the like.

ii) The moving part can be expressed by the rotation value of the joint. The rotation value of each joint can be described as the Euler rotation value rotating in the X, Y, and Z axes. Twenty-one rotational values can be recorded, and thirty information per second can be recorded in such a manner that the next rotational value is recorded.

Therefore, the motion data consisting of the shape portion and the motion portion may be applied to each joint of the character to be represented by animation. In addition, depending on the character's body classification, even if the character has a difference in size from the basic T-shape, such as a fat character or a dwarf character, the motion transformation engine performs motion transformation by the motion deformation engine to be described later to suit the unique characteristics of the character. The modified motion data can be generated.

The present invention includes a character parameter data unit for storing physical information of a character to which the motion data is to be applied.

The physical information of the character means a character parameter, which expands the information corresponding to the shape of the motion data to further expand the position of the joint, the joint length, the mass of the joint, the center of gravity, the volume of the joint, and the rotational mass (inertia). Information including physical properties such as momentum). That is, it can be said that it contains essential information to be compared before the animation to which the motion part of the motion data is applied to the character.

In addition, the parameter of the character may be classified into parameters according to the physical classification of the character and the influence of external factors may be stored in the character parameter data unit.

The physical classification is classified according to the body type of the character. For example, the physical classification may be classified into a fat character, a slender character, a giant character, a dwarf character, a character whose body part is exaggerated, and the like to input and store parameters.

Parameters due to external factors, such as hats, sneakers, high heels, sportswear, suits, and other miscellaneous goods, tools such as swords, shields, axes, guns, etc. It may mean a parameter for such.

Therefore, when the character parameter is input to the motion deformation engine, the motion data considering the character parameter may be calculated to generate the modified motion data.

The present invention includes a motion deformation engine that calculates modified motion data using the motion data and the physical information of the character.

In the motion of the character to which the motion data is applied, the motion deformation engine measures the amount of movement based on physical properties such as the speed of movement of the character, the amount of movement, the angular movement, and the like to compensate for the violation of the actual movement to generate motion data that is close to the actual movement. It plays a role.

That is, the motion transformation engine that transforms the motion data receives the motion data from the motion data unit and uses the parameter of the character input from the character parameter data unit so that it can be directly applied to the character animation. Motion data can be calculated.

In the present invention, the motion deformation engine unit, using the calculation unit for calculating the physical information by applying the motion data to the character and modifying the motion data using the constraints caused by the influence of external factors to be applied to the character to the physical information. It includes a motion deformation unit.

The motion deformation engine unit may include a calculation unit analyzing the motion of the joint and a motion deformation unit obtaining the rotation value of the joint from the calculated information.

In the motion of the character to which the motion data is applied, the calculation unit obtains physical information such as motion speed, motion energy, angular motion energy, momentum, and angular motion for each joint of the character, and inputs a constraint condition by an external influence factor. The motion data may be transformed and the rotation value of each joint of the character may be extracted using the transformed motion. That is, the motion data may be applied to the character by converting the motion of each joint into attributes of the character joint and applying the animation motion to keep it physically significant.

The external influence element is a hat, sneakers, high heels, sportswear, suits and other items worn by the character, such as a knife, a shield, an axe, a gun and other tools that the character can carry, such as a concrete ground, It can refer to elements of the surrounding environment such as soil composed of soil, water, and air. Detecting and inputting a constraint caused by such an external influence element enables the transformation of motion data.

For example, the character's motion landing on the soil composed of soft soil can be expressed to feel a soft landing feeling, and the character's motion landing on a place composed of hard concrete ground can be expressed to feel hard impact.

The motion transformation unit performs a role of outputting and storing the modified motion data by directly applying the rotation value of each joint to the character after the calculation is completed until the step of extracting the rotation value of each joint of the character. Can be. In other words, the deformed motion data can be finally generated and stored and used directly in animation production.

The present invention relates to a motion retargeting system and a method of using the same, wherein motion retargeting refers to a method of applying motion capture data to a character appearing in an animation or the like.

The present invention comprises the steps of storing the motion data in which the physical information of the human body is added to the motion capture data obtained from the motion of the human body in the motion data unit, the physical information of the character to apply the motion data to the character parameter data unit, Inputting the motion data and the physical information of the character to a motion deformation engine and calculating the modified motion data using the input motion data and the physical information of the character to the motion deformation engine. Retargeting method.

In the present invention, the step of calculating the transformed motion data using the input motion data and the character information in the motion transformation engine unit, the step of obtaining the motion of the character by applying the motion data to the character, each joint of the character Obtaining physical information based on the following, inputting a constraint caused by the influence of an external element to which the character is to be applied, applying the constraint to the character, and deformed motion of the character to which the constraint is applied. Motion retargeting method comprising the step of extracting the rotation values of all the joints of the character using.

The present invention further includes the step of calculating and storing the deformed motion data of the character after extracting rotation values of all joints of the character using the deformed motion of the character to which the constraint is applied. Retargeting method.

To sum up the above process, each part of the human body is modeled by the connection of individual objects and viewed as the motion of all joints, and when motion capture data is applied, the human body is decomposed into force and torque, kinetic energy and rotational motion. It can be said to change the physical properties of the character to be applied to the exercise to configure the movement for the actual character.

The present invention includes a computer readable recording medium for recording a computer program for executing the above-described motion retargeting method.

According to the present invention, unlike the prior art, each part of the human body is modeled by the connection of individual objects to see the motion of all joints, and when applying the data obtained by motion capture, the motion of the human body is the force and torque, kinetic energy and rotation Since it is composed of the motion suitable for the actual character by changing the physical property of the character to be applied after the decomposition into motion, there is an effect that high-quality motion data can be generated.

In addition, according to the present invention, since the motion data is generated by reflecting the physical properties of the character, the motion data can be modified and applied according to the characteristics of the character, and the effect of adding the weight of the character's motion is reflected. The production of realistic characters becomes possible, and the range of application of animation production using motion data is expanded.

 According to the present invention, in the method of transforming motion data, it is calculated using a motion equation, the property of the character to be used for calculation is extracted as a parameter, and the motion deformation engine automatically generates modified motion data. The cost is dramatically reduced.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a flowchart illustrating a motion retargeting method according to an embodiment of the present invention.

First, motion data generated by digitizing the motion of the human body is added to physical information of the human body, such as weight, height, joint length, center of gravity position, moment of inertia of the joint, and the like. Steps to save is performed (S101).

Thereafter, storing the physical information of the character, that is, the character parameter, including the physical properties such as the joint length, the joint mass, the center of gravity, the volume occupied by the joint, and the rotational mass, as well as the position of the character joint, in the character parameter data unit. Step on (S102)

After such a step, when the motion data of the motion data unit and the physical information of the character parameter of the character parameter data unit is input to the motion engine deformation unit (S103), the full-scale motion data transformation process is started.

First, the input motion data and character information are transmitted to a calculation unit including a motion engine deformation unit, and the calculation unit obtains motion information of a character to which the motion data is applied. (S104)

Thereafter, the physical information, such as speed, kinetic energy, angular exercise energy, exercise amount, and angular exercise amount, is obtained for each joint of the character based on the exercise information of the character.

Thereafter, a step of searching for and inputting the constraints caused by the influence of the character and the external elements to be applied to the character is performed (S106). Miscellaneous goods and tools such as knives, shields, axes, guns, etc., which can be carried by the character, and the space in which the character is active, that is, elements such as concrete ground, soil composed of soil, water, and the surrounding environment such as the air. Searching for and inputting the constraints caused by these external influence factors, it is possible to generate the deformation motion data applicable to the character that can perform a natural motion under these conditions.

Through such a process, the step of applying the constraint condition to the character to which the motion data is applied is performed (S107). In this process, not only the generation of motion data in consideration of the constraint condition, but also physical reference based on each joint of the character. Compensation is automatically performed to be closer to the actual motion by comparing the information with the physical information about the motion of the object having the same weight in the real world, and the motion data may be modified in consideration of the above limiting factor.

Then, after extracting the rotation values of all the joints of the character by using the deformed motion (S108), by applying the rotation values of all the joints to the character once again to calculate and output the modified motion data After the step of storing (S109), the execution of the motion retargeting method according to an embodiment of the present invention is completed.

2 is a block diagram showing the configuration of a motion retargeting system according to an embodiment of the present invention.

The motion data unit 210 adds motion data including information of the height, weight, joint position, joint length, joint center of gravity position, and moment of inertia of the joint to motion capture data obtained from the human body. It stores and transmits it to the calculation unit 240 of the motion deformation engine 230.

The character parameter data unit 220 stores character information about physical properties such as the position of the character as well as the length of the joint, the mass of the joint, the center of gravity, the volume occupied by the joint, and the rotational mass (inertia momentum). It may serve to transmit this to the calculation unit 240 of the motion deformation engine 230.

The motion transformation engine 230 measures motions based on physical properties such as motion speed, motion amount, angular motion amount of the character to which motion data is applied, and corrects violations with actual motion to generate motion data approximating actual motion. Can be done.

The motion deformation engine 230 may include a calculation unit 240 and a motion deformation unit 250. In the motion of the character to which the motion data is applied, the calculation unit 240 includes a speed and a motion for each joint of the character. After acquiring physical information such as energy, angular kinetic energy, momentum, and angular momentum, input constraints by external environment to transform motion data, and extract the rotation value of each joint of the character using the modified motion. Can be done.

The motion transformation unit 250 may serve to output and store the finally deformed motion data by applying the rotation value of each joint of the character to the character once again.

The deformed motion data 260 output through the above process is high quality motion data in which the weight of the character, the balance of motion, and the precise feeling by motion capture are expressed.

3 is an exemplary view showing a shape of a motion data and a clip information window according to an embodiment of the present invention.

The shape 320 of the motion data includes basic posture information of the T-shape as basic form information of the main joints of the human body, and the joint information may be described as a relative position value of the parent joint and the child joint.

The clip information window 310 displays an information window for designating each joint part in the shape 320 of the motion data. The user may designate each joint part of the shape 320 of the motion data to generate a required motion. .

4 is an exemplary view illustrating a shape in which motion data is operated according to an embodiment of the present invention.

The motion data can be designated by the user through the clip information window 310 to generate the required motion, and the motion part can be expressed by the rotation value of the joints. It can be described as Euler rotation value rotating in the Z axis. Twenty-one rotational values can be recorded, and thirty information per second can be recorded in such a manner that the next rotational value is recorded.

5 is an exemplary diagram illustrating an animated character synthesized using motion data and a character according to an embodiment of the present invention.

The user can create the shape 510 of the motion data required by the user, and finally, the animation character 530 can be generated in consideration of the constraints caused by the physical properties of the character 520 and external influence factors. have.

6 is an exemplary view showing the relative position and the center of gravity of the joint of the character according to an embodiment of the present invention.

A parameter of a character is information including not only the position of the joint but also physical properties such as the joint length, the mass of the joint, the center of gravity of the joint, the volume occupied by the joint, and the rotational mass (inertia momentum). Due to the parameters being considered, high quality character animation can be generated. In FIG. 6, the center of gravity 610 of the joint of each character animation is displayed.

The present invention has been described above in connection with specific embodiments of the present invention, but this is only an example and the present invention is not limited thereto. Those skilled in the art can change or modify the described embodiments without departing from the scope of the present invention, and within the equivalent scope of the technical spirit of the present invention and the claims to be described below. Various modifications and variations are possible.

1 is a flowchart illustrating a motion retargeting method according to an embodiment of the present invention.

Figure 2 is a block diagram showing the configuration of a motion retargeting system according to an embodiment of the present invention.

3 is an exemplary view showing a shape of a motion data and a clip information window according to an embodiment of the present invention.

4 is an exemplary view showing a shape in which motion data is operated according to an embodiment of the present invention.

5 is an exemplary diagram illustrating an animated character synthesized using motion data and a character according to an embodiment of the present invention.

6 is an exemplary view showing the relative position and the center of gravity of the joint of the character according to an embodiment of the present invention.

{Description of major symbols in the drawing}

210: motion data part

220: character parameter data portion

230: motion deformation engine unit

240: calculation unit

250: motion deformation

260: deformed motion data

310: Clip Information Window

320, 510: shape of motion data

520: the shape of the character

530: shape of the animated character

610: center of gravity of the character's joints

Claims (7)

A motion data unit for storing motion data; A character parameter data unit for storing physical information of a character to which the motion data is to be applied; And A motion deformation engine unit configured to calculate modified motion data using the motion data and the physical information of the character; Motion retargeting system comprising a. The method of claim 1, wherein the motion data, Motion retargeting system comprising adding information of height, weight, position of joint, length of joint, center of gravity of joint and moment of inertia of joint to motion capture data obtained by digitizing the movement of human body . The method of claim 1, wherein the motion deformation engine unit, A calculator for calculating physical information by applying the motion data to the character; And A motion transformation unit for transforming the motion data using a constraint condition caused by an influence of an external element to be applied to the character to the physical information; Motion retargeting system comprising a. Storing motion data in which motion information including the physical information of the human body is added to the motion capture data obtained from the motion of the human body; Storing physical information of a character to which the motion data is to be applied to a character parameter data unit; Inputting physical information of the motion data and the character into a motion deformation engine; And Calculating modified motion data by using the input motion data and physical information of a character in the motion deformation engine unit; Motion retargeting method comprising a. The method of claim 4, wherein the calculating of the modified motion data by using the input motion data and the character information by the motion deformation engine comprises: Obtaining the motion of the character by applying the motion data to the character; Obtaining physical information based on each joint of the character; Inputting a constraint caused by an influence of an external element to which the character is applied; Applying the constraint to the character; And Extracting rotation values of all joints of the character using the deformed motion of the character to which the constraint is applied; Motion retargeting method comprising a. The method of claim 5, wherein after extracting rotation values of all the joints of the character using the modified motion of the character to which the constraint is applied, Motion retargeting method comprising the step of calculating and storing the modified motion data of the character. A computer-readable recording medium for recording a computer program for executing the method according to any one of claims 4 to 6.

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