KR20120110439A - Device and method for generating foam particle - Google Patents

Abstract

PURPOSE: A bubble particle generating device and a bubble particle generating method are provided to express bubbles generated on a surface of fluid. CONSTITUTION: A fluid simulation module(10) models a fluid volume and updates a velocity field and a surface location of the fluid volume. A velocity field change analyzing module(20) analyzes a change of the velocity field. A water surface change analyzing module(30) analyzes a change of the surface location of the fluid volume. A bubble particle generating module(40) generates a bubble particle. A bubble particle simulation module(50) simulates the bubble particle. [Reference numerals] (10) Fluid simulation module; (20) Velocity field change analyzing module; (30) Water surface change analyzing module; (40) Bubble particle generating module; (50) Bubble particle simulation module

Description

Foam particle generating device and foam particle generating method {Device and method for generating foam particle}

Embodiment according to the concept of the present invention relates to a bubble particle, and in particular to a bubble particle generation device and bubble particle generation method for more effectively performing the liquid animation (liquid animation) used for generating the visual special effects of the animation or movie It is about.

Recently, fluid expression is an important element in a movie or animation, and various technologies have been developed for the fluid expression. However, these various technologies do not meet the needs of general users due to technical constraints.

In particular, there is a difficulty in expressing detailed elements that occur on water surfaces such as bubbles.

Accordingly, a technical problem of the present invention is to provide a bubble particle generation device and a bubble particle generation method capable of generating bubble particles by analyzing the velocity field updated by the fluid simulation and the surface position of the updated fluid volume.

Bubble particle generation apparatus according to an embodiment of the present invention is a fluid simulation module for modeling a fluid volume (liquid volume) and updating the velocity field and the surface position of the fluid volume, by analyzing the change in the velocity field Velocity field change analysis module for generating first position information for generating foam particles, and water surface change for generating second position information for generating foam particles by analyzing the change of the surface position of the fluid volume. An analysis module, a bubble particle generation module for generating the bubble particles according to the first position information and the second position information, and a bubble particle simulation module for simulating the bubble particles using the velocity field.

The surface location of the fluid volume is represented by a level set method.

The water surface change analysis module extracts normal information and curvature information of the surface position of the fluid volume and generates the second position information according to the extracted normal information and the curvature information.

Each of the first position information and the second position information is represented as an area.

According to an embodiment, the bubble particle generation module determines an amount of the bubble particle based on the first position information and the second position information.

According to an embodiment, the bubble particle generation module determines the life of the bubble particle based on the first position information and the second position information.

The bubble particle generation module uses a noise function to determine the life of the bubble particle.

According to an embodiment, the bubble particle generation module may remove the bubble particle or increase the age of the bubble particle according to the life of the bubble particle.

In accordance with another aspect of the present invention, there is provided a method for generating bubble particles, in which a fluid simulation module models a fluid volume, updates a velocity field and a surface position of the fluid volume, and a velocity field change analysis module. Analyzing the change in the velocity field to generate first positional information in which foam particles are to be generated, and a surface change analysis module analyzes the change in position of the surface of the fluid volume to generate the foam particles. Generating second position information, bubble particle generation module generating the bubble particles according to the first position information and the second position information, and bubble particle simulation module using the velocity field; Simulating the step.

The generating of the second position information may include extracting normal information of the fluid volume by tracking the surface position of the fluid volume, extracting curvature information using the extracted normal information, and extracting the extracted normal information. The second position information is generated according to the normal information and the extracted curvature information.

The surface location of the fluid volume is represented by a level set method.

A computer-readable recording medium according to an embodiment of the present invention records a program capable of executing the method for generating bubble particles.

The bubble particle generating device and the bubble particle generating method according to the embodiment of the present invention enable the bubble expression generated on the fluid surface during the fluid phenomenon that could not be easily expressed by generating the bubble particle, thereby making it possible to easily make realistic animations or images accordingly. There is an effect that can be provided quickly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to more fully understand the drawings recited in the detailed description of the present invention, a detailed description of each drawing is provided.
1 is a schematic block diagram of a bubble particle generating device according to an embodiment of the present invention.
2 illustrates a grid cell according to an embodiment of the present invention.
3 illustrates an embodiment of a level set representation according to an embodiment of the present invention.
4 is a flowchart illustrating a bubble particle generation operation according to an embodiment of the present invention.

It is to be understood that the specific structural or functional descriptions of embodiments of the present invention disclosed herein are only for the purpose of illustrating embodiments of the inventive concept, But may be embodied in many different forms and is not limited to the embodiments set forth herein.

Embodiments in accordance with the concepts of the present invention are capable of various modifications and may take various forms, so that the embodiments are illustrated in the drawings and described in detail herein. It should be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms disclosed, but includes all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are intended to distinguish one element from another, for example, without departing from the scope of the invention in accordance with the concepts of the present invention, the first element may be termed the second element, The second component may also be referred to as a first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions describing the relationship between components, such as "between" and "immediately between," or "neighboring to," and "directly neighboring to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises ", or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings.

1 is a schematic block diagram of a bubble particle generating device according to an embodiment of the present invention.

Referring to FIG. 1, the bubble particle generating device 1 includes a fluid simulation module 10, a velocity field change analysis module 20, a water surface change analysis module 30, a bubble particle generation module 40, and a bubble particle. Simulation module 50 is included.

Although the fluid simulation module 10 is illustrated as being included in the bubble particle generation device 1 in FIG. 1, the fluid simulation module 10 may be implemented as a separate device.

In the present specification, the bubble particle generating device 1 may be a general PC or computer system, and may be implemented as hardware (H / W), software (S / W), or a combination of the hardware and the software. .

In the present specification, a module may mean a functional or structural combination of hardware for performing a technical idea and software for driving the hardware, according to an embodiment of the present invention.

For example, the module may mean a logical or functional unit of predetermined program code and a hardware resource for executing the program code, and does not necessarily mean physically connected program code or one kind of hardware.

The fluid simulation module 10 models and animates the fluid.

The fluid simulation module 10 models a static environment into a voxel grid. A voxel is a set of graphic information that defines a point in 3D space.

2 illustrates one grid cell according to an embodiment of the present invention.

Referring to FIG. 2, the fluid is represented by a grid 11 of rectangular shape with a side length Δτ.

According to an embodiment, the fluid may be represented by another type of grid.

The grid 11 has a pressure variable in the center and shares the speed variable with the neighbors of the grid 11. The fluid velocity field u includes a plurality of vectors u _i , u _k , u _{j +1} .

Referring to FIG. 1, the fluid simulation module 10 updates the velocity field by calculating the following equation (1).

[Equation 1]

는 점도(viscosity)를,

는 그래디언트 연산자를, u는 상기 속도장을,

는 밀도(density)를, p는 압력을, g는 중력을 나타낸다.Where u _t is the vector of the velocity field,

Is the viscosity,

Is the gradient operator, u is the velocity field,

Where is density, p is pressure, and g is gravity.

)는 수학식 2와 같이 나타낼 수 있다.The gradient operator (

) Can be expressed as in Equation 2.

&Quot; (2) "

)는 도 2의 (i,j,k) 좌표와 수학식 2를 이용하여 표현될 수 있다.Here, each of x, y, and z means the x-axis direction, the y-axis direction, and the z-axis direction in FIG. 2. Gradient operator (

) May be expressed using the (i, j, k) coordinates of FIG.

), 대류(convection), 밀도(

), 압력(p), 또는 중력(g)의 영향 때문에 변할 수 있다. 또한 상기 속도장(u)은 유체 변화에 따라 변화하므로 유체 시뮬레이션 모듈(10)은 적분 시간 스텝을 통해 상기 수학식 1을 연산하여 상기 속도장을 업데이트한다. The velocity field is the viscosity (

), Convection, density (

), Pressure (p), or gravity (g) may change. In addition, since the velocity field u changes as the fluid changes, the fluid simulation module 10 updates the velocity field by calculating Equation 1 through an integration time step.

The fluid simulation module 10 calculates Equation 3 to enhance incompressibility.

&Quot; (3) "

는 상기 그래디언트 연산자를, u는 상기 속도장을 의미한다.here,

Denotes the gradient operator and u denotes the velocity field.

3 illustrates an embodiment of a level set representation according to an embodiment of the present invention.

1 and 3, the fluid simulation module 10 uses a level set method to track the evolution of the surface of the fluid volume. The surface of the fluid volume refers to a line or face in which the fluid maintains its shape in two-dimensional or three-dimensional space and forms a boundary with the outside.

표현된다.Isolating function

Is expressed.

Where P is the time t is a point in space.

The fluid simulation module 10 uses equation 4 to update the surface position of the fluid volume.

&Quot; (4) "

는 대류를 의미한다.remind

Means convection.

를 트랙킹(tracking)함으로써 변화된다.The surface position of the fluid volume continues

Is changed by tracking.

The velocity field change analysis module 20 analyzes the variation of the velocity field to generate first position information in which bubble particles are to be generated.

In fact, bubbles on the water's surface are caused by a sudden change in velocity of the fluid flowing through it. When a constant velocity fluid flows in a straight line, bubbles rarely occur.

However, a large amount of bubbles are generated when there is an obstacle that obstructs the fluid velocity or when the fluid flows in a curved section.

By imitating this natural phenomenon, an identifier is planted in a section or curve section in which an obstacle exists.

However, the presence of a change in velocity of the fluid does not necessarily result in bubbles. Therefore, the velocity field change analysis module 20 also considers these factors and reflects them in the analysis.

The water surface change analysis module 30 analyzes the change of the surface position of the fluid volume to generate second position information for generating the bubble particles.

The water surface change analysis module 30 extracts normal information and curvature information of the surface position of the fluid volume and generates the second position information according to the extracted normal information and the curvature information.

Since bubble particles must be present on the water surface, the surface position of the fluid volume is represented by a level set method.

The water surface change analysis module 30 uses the surface position of the fluid volume to create a filter at a position where bubble particles can be generated and to generate an identifier at that position.

The surface change analysis module 30 extracts normal information by tracking the surface position of the fluid and generates curvature information using the extracted normal information.

The water surface change analysis module 30 generates second position information according to the extracted normal information and the generated curvature information.

According to an embodiment, the water surface change analysis module 30 may generate second position information according to the change of the normal information and the change of the curvature information.

The second position information includes information on the amount of bubble particles to be generated as well as position information on which bubble particles are to be generated.

The bubble particle generation module 40 generates the bubble particle according to the first position information and the second position information.

Each of the first location information and the second location information is represented by an area instead of a specific numerical value.

The bubble particle generation module 40 determines the exact position at which the bubble particle is to be generated by using random numbers in each of the first position information and the second position information.

According to an embodiment, the bubble particle generating device 1 may further include a random number generator (not shown) to generate the random number.

The bubble particle generation module 40 determines the amount of the bubble particle according to the first position information and the second position information.

The bubble particle generation module 40 determines the life of the bubble particle according to the first position information and the second position information, and a noise function may be used to determine the life of the bubble particle.

When the noise function is used, the bubble particle generation module 40 may generate more realistic bubble particles.

The bubble particle generation module 40 may remove the bubble particles or increase the age of the bubble particles according to the life of the bubble particles.

According to an embodiment, even when the life of the bubble particles is not reached, the bubble particle generation module 40 may identify and remove the bubble particles when they are far from the surface position of the fluid volume.

The bubble particle simulation module 50 simulates the bubble particle using the velocity field output from the fluid simulation module 10.

The bubble particle simulation module 50 generates a current frame including the bubble particles as a result of the simulation and transfers the simulation result values to the fluid simulation module 10 for generation of a next frame including the bubble particles.

The fluid simulation module 10 remodels and animates the fluid that has changed over time.

4 is a flowchart illustrating a bubble particle generation operation according to an embodiment of the present invention.

1 to 4, the fluid simulation module 10 models a fluid volume and updates a velocity field and a surface position of the fluid volume (S10).

The velocity field change analysis module 20 analyzes the variation of the velocity field to generate first position information in which bubble particles are to be generated (S20).

The water surface change analysis module 30 analyzes the change in the position of the surface of the fluid volume to generate second position information for generating the bubble particles (S30).

The bubble particle generation module 40 generates the bubble particle according to the first position information and the second position information (S40).

The bubble particle simulation module 50 simulates the bubble particle for the current frame using the velocity field (S50).

The bubble particle simulation module 50 determines whether the current frame is larger than an arbitrary threshold (S60), and repeatedly performs operations S10 to S50 until the current frame is larger than an arbitrary threshold.

Accordingly, the bubble particle simulation module 50 may simulate bubble particles for a plurality of frames.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

One; Bubble particle generator
10; Fluid simulation module
20; Velocity field change analysis module
30; Water Surface Change Analysis Module
40; Bubble Particle Generation Module
50; Bubble Particle Simulation Module

Claims (12)

A fluid simulation module that models a fluid volume and updates the velocity field and the surface position of the fluid volume;
A velocity field change analysis module configured to analyze the change in the velocity field to generate first position information for generating foam particles;
A water surface change analysis module for analyzing the change of the position of the surface of the fluid volume to generate second position information for generating the bubble particles;
A bubble particle generation module configured to generate the bubble particles according to the first position information and the second position information; And
And a bubble particle simulation module for simulating the bubble particles using the velocity field. The method of claim 1, wherein the surface position of the fluid volume,
Bubble particle generation device represented by a level set method. The method of claim 1, wherein the water surface change analysis module,
And extracting normal information and curvature information of the surface position of the fluid volume and generating the second position information according to the extracted normal information and the curvature information. The method of claim 1, wherein each of the first location information and the second location information,
Bubble particle generating device represented as an area. The method of claim 1, wherein the bubble particle generation module,
And determine the amount of the bubble particles based on the first position information and the second position information. The method of claim 1, wherein the bubble particle generation module,
Bubble particle generation apparatus for determining the life of the bubble particles in accordance with the first position information and the second position information. The method of claim 6, wherein the bubble particle generation module,
And use a noise function to determine the lifetime of the bubble particles. The method of claim 6, wherein the bubble particle generation module,
And remove the bubble particles or increase the age of the bubble particles according to the life of the bubble particles. The fluid simulation module models a fluid volume and updates the velocity field and the surface position of the fluid volume;
Analyzing, by the velocity field change analyzing module, the change in the velocity field to generate first position information for generating foam particles;
A water surface change analysis module analyzing the change of the surface position of the fluid volume to generate second position information for generating the bubble particles;
Generating, by the bubble particle generation module, the bubble particle according to the first position information and the second position information; And
And a bubble particle simulation module for simulating the bubble particles using the velocity field. The method of claim 9, wherein the generating of the second location information comprises:
Extracting normal information of the fluid volume by tracking the surface position of the fluid volume;
Extracting curvature information using the extracted normal information; And
And generating the second position information according to the extracted normal information and the extracted curvature information. 10. The method of claim 9, wherein the surface location of the fluid volume is
Bubble particle generation method represented by level set method. A computer-readable recording medium having recorded thereon a program capable of executing the bubble particle generation method according to any one of claims 9 to 11.

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