Chemical experiment simulation system and method based on virtual reality

Abstract

The invention discloses a chemical experiment simulation system and method based on virtual reality, relates to the technical field of chemical experiment simulation, and solves the problems that in the prior art, complex environments and variable conditions in a real laboratory cannot be comprehensively simulated, and dynamic simulation of chemical reactions in the experiment process is lacked. And the problem of lack of sense of reality in operation details is solved. A chemical laboratory model and a chemical instrument model are built through the scene building unit. During a chemical experiment, a chemical instrument model is grabbed or placed through the article picking and placing module, collision detection is performed through the collision detection unit, and a corresponding chemical reaction particle special effect in the special effect unit is triggered when a correct collision detection operation is completed. And the Actor is set to hide direct switching nodes in the game to display and hide objects, and corresponding explicit and implicit are triggered through different collision detections, so that numerous chemical experiments including a combustion experiment of sulfur and an experiment of preparing oxygen from potassium permanganate are simulated.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical experiment simulation, and in particular to a chemical experiment simulation system and method based on virtual reality. Background Art

[0002] Chemical laboratories are important places for providing chemical experimental conditions and conducting scientific research. Here, through experimental operations, experimenters can not only verify theoretical knowledge, but also cultivate scientific thinking and experimental skills. However, there are also many hidden safety hazards in the laboratory. Due to the unskilled skills and improper operation of experimenters, these hidden dangers may turn into serious safety accidents at any time. For example, improper mixing of chemical reagents and misoperation of experimental equipment may lead to serious consequences such as fire, explosion and even poisoning. Therefore, ensuring laboratory safety and improving people's experimental skills are challenges faced by educators and learners. It is in this context that the application of virtual reality technology is particularly important. Through virtual reality simulation of chemical laboratories, experimenters can perform experimental operations in a safe environment without worrying about the dangers that may occur in real experiments. At the same time, this technology can also provide a more intuitive and interactive learning experience to help experimenters better master chemical experimental skills.

[0003] Although virtual reality technology has broad application prospects in chemical laboratory simulation teaching, the simulation systems currently on the market have single functions and cannot fully simulate the complex environment and changing conditions in real laboratories. Moreover, most systems only provide simple operations of basic chemical reagents and instruments, lack dynamic simulation of chemical reactions during the experiment, or lack realism in operation details, such as precise operation of experimental equipment and precise simulation of chemical reactions. These problems limit the actual application effect of simulation systems in teaching, and also affect people's enthusiasm and effect of learning chemical experiments through simulation systems. Therefore, developing a chemical laboratory simulation system with comprehensive functions, realistic operation, and the ability to meet teaching needs is of great significance to improving people's experimental skills and laboratory safety awareness.

[0004] In view of this, a chemical experiment simulation system and method based on virtual reality is needed. Summary of the invention

[0005] In view of the problem that the existing technology cannot fully simulate the complex environment and changeable conditions in a real laboratory, lacks dynamic simulation of chemical reactions during the experiment, and thus lacks realism in operation details, the present invention provides a chemical experiment simulation system and method based on virtual reality, which can simulate various chemical reactions in chemical experiments through building chemical laboratory models and chemical instrument models, and through special effects and animations, to achieve various basic chemical experiments. The specific technical solution is as follows:

[0006] A chemical experiment simulation system based on virtual reality, comprising:

[0007] A scene building unit, using 3D modeling and animation software to build a chemical laboratory model and a chemical instrument model and import them into the game engine, wherein the chemical laboratory model includes a table and the chemical instrument model includes an alcohol lamp;

[0008] The special effect unit includes a flame special effect production module, wherein the flame special effect production module simulates the flame effect through the particle system of the game engine;

[0009] The collision detection unit performs collision detection based on the game engine and automatically triggers corresponding operations when the corresponding collision is triggered;

[0010] The VR interaction unit includes a module for picking up and placing items and a display and hiding module. The module for picking up and placing items establishes grabbing events and releasing events, and uses a handle to pick up and release the chemical instrument. The display and hiding module displays and hides objects by setting the Actor to hide in the game and directly switches the node, and triggers the corresponding display and hiding through different collision detections.

[0011] Preferably, the operation process of the pick-up and place-item module using the handle to pick up and release the chemical instrument is as follows:

[0012] Create a new blueprint interface, add pick-up and release functions, add input parameters to the pick-up function, and select the variable pin type as the scene component; create a new blueprint Actor, set the collision properties, and add object pick-up and release functions; enter the left and right handle actions in the VRPawn blueprint, and when the target is set to approach the object, determine whether the object implements the method of the interface class, and then execute the grab and release functions.

[0013] Preferably, the specific operations of the existing module are as follows:

[0014] Call the event to start executing the event, execute the connection to set the Actor to be hidden in the game, check Boolean, and connect the target to hide the Actor; call the collision overlap event of the collision box, convert the type to Huochai_2, check whether the collision is Huochai_2, connect the Object category back to the Object Actor, use the delay node, call to set the Actor to be hidden in the game, and connect the target Actor.

[0015] Preferably, the VR interaction unit further includes a homing module, which is used to restore the chemical instrument to its original position. The manufacturing process thereof is as follows:

[0016] Create a new Boolean variable guiwei, a transformation variable Taeget, a floating-point variable Delta Seconds, and a floating-point variable Interp Speed. Call the event Tick to execute a connection to a sequence, and the sequence execution is connected to a branch. In the branch, the Condition is connected to the newly created guiwei Boolean variable, the branch True execution is connected to set the value of the variable Delta Second, and the floating-point node is connected to the floating point of the event Tick;

[0017] Call the Set Actor Transformation node, connect and set the value of the variable Delta Second. In the Set Actor Transformation node, connect the target to the Actor to be relocated, get the Actor's transformation, transform T to interpolate, set the target transformation of the variable Taeget, the time since the last tick of the variable Delta Seconds, and the interpolation speed of the variable Interp Speed.

[0018] In the overlap event of the collision box, execute the connection type conversion to Yaoping1, check whether the collision is Yaoping1, then execute the connection to set the value of the variable guiwei and check Guiwei.

[0019] Preferably, the flame special effect production module is used to produce flame special effects, and the production process is as follows:

[0020] Production of flame material: Use the particle system in UE4 to make flames, create a flame material ball, change the material's blending mode to Additive, and check Use particle Sprite in the purpose; import the flame texture map and connect it to the B of the Multiply node, connect the A of the Multiply node to a 3D node to set the color, and then connect the Multiply node to the self-luminous color of the material; create a new 1D node, modify its value and connect it to the opacity of the material;

[0021] Select the prepared flame material in the emitter material of the particle system, modify the required, generated, initial size, initial speed and other values ​​to get a flame particle special effect.

[0022] Preferably, it also includes a level sequence animation unit, the level sequence animation module is used to make animations, and plays animations when the corresponding collision is triggered, the level sequence animation unit includes a neutralization reaction color change production module, the neutralization reaction color change production module is used to make material color change animations, and the specific process is as follows:

[0023] Create a new material, give it a base color, convert it to a parameter, and rename it to Color;

[0024] Create a new material parameter set, add a vector parameter, name it Color, select the material ball, replace the base color with the newly created material parameter set, and select Color as the parameter name;

[0025] Create a new level sequence, drag the material parameter set into it, add the Color attribute, modify its color value and set keyframes.

[0026] Preferably, it also includes a level sequence animation unit, the level sequence animation module is used to make animations, and plays animations when the corresponding collision is triggered, the level sequence animation unit includes a plastic bottle explosion production module, the plastic bottle explosion production module is used to make a plastic bottle explosion display animation, the specific process is as follows:

[0027] Create a new blueprint Actor, add a scene component and set the large plastic bottle static mesh as its subset, add a spline, add a function named fly, add a floating-point variable Distance, get the Scene's Get Scene Position and Rotation nodes, get the distance position along the spline, get the distance rotation along the spline, connect the target to the spline, use the floating-point variable Distance to control its position and rotation transformation, and select the world coordinates from the enumeration value;

[0028] Select the variable Distance and check Public to Cutscene to expose it to Sequence. Connect the Fly function in the constructor to make the Fly function calculate from the beginning;

[0029] Edit the spline to the required motion path;

[0030] Create a new Sequence, add the variable Distance property and repeater event, set a keyframe for the Distance value, match the event and keyframe lengths, call the Fly function in the event function, and check the activation event call in the editor;

[0031] Use collision detection to implement the explosion and knockback animation after the experimental operation.

[0032] A chemical experiment simulation method based on virtual reality, applied to the system as described above, comprises the following steps:

[0033] Build chemical laboratory models and chemical instrument models through scene building units. The chemical instrument models include alcohol lamps, test tubes, combustion spoons, gas collecting bottles, beakers, matches, sulfur, medicine spoons, glass pieces, and wide-mouth bottles.

[0034] During the chemical experiment, grab or place the chemical instrument model through the pick-up and place item module;

[0035] The collision detection unit performs collision detection based on the game engine, and triggers the corresponding chemical reaction particle special effects in the special effect unit after completing the correct collision detection operation;

[0036] By setting the Actor to be hidden in the game, you can directly switch the node to display and hide the object, and trigger the corresponding display and hiding through different collision detection.

[0037] A computer-readable storage medium includes a stored program, wherein when the program is run, the device where the computer-readable storage medium is located is controlled to execute the intelligent detection construction method as described above.

[0038] A processor is used to run a program, wherein the program executes the intelligent detection construction method as described above when it is run.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention builds a chemical laboratory model and a chemical instrument model through a scene building unit. During a chemical experiment, the chemical instrument model is grabbed or placed through a pick-up and place item module, and collision detection is performed through a collision detection unit. After completing the correct collision detection operation, the corresponding chemical reaction particle special effect in the special effect unit is triggered, and the Actor is set to hide in the game to directly switch nodes to display and hide objects, and the corresponding display and hiding are triggered through different collision detections. Then, many chemical experiments including sulfur combustion experiments, potassium permanganate oxygen production experiments, dust explosion experiments, and neutralization reaction experiments are simulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0042] Figure 1 Blueprint logic diagram for grabbing and releasing;

[0043] Figure 2 Flowchart for instrument homing and collision triggering;

[0044] Figure 3 A blueprint logic diagram for instrument placement;

[0045] Figure 4 To hide and collide the display flow chart;

[0046] Figure 5 Blueprint logic diagram shown for starting to implement hiding and collision detection;

[0047] Figure 6 Play animation blueprint logic blueprint for spline movement and collision detection;

[0048] Figure 7 This is the system block diagram of the VR chemical laboratory simulation system;

[0049] Figure 8 This is the flow chart of sulfur combustion experiment;

[0050] Fig. 9 This is the dust explosion experiment flow chart;

[0051] Fig.10 This is the dust explosion experiment flow chart;

[0052] Fig.11 This is the flow chart of the neutralization reaction experiment. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0055] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0056] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0057] In one embodiment of the present invention, a chemical experiment simulation system based on virtual reality is provided, comprising:

[0058] 1. A scene building unit, using 3D modeling and animation software to build a chemical laboratory model and a chemical instrument model and import them into the game engine, wherein the chemical laboratory model includes a table and the chemical instrument model includes an alcohol lamp;

[0059] 2. A special effect unit, including a flame special effect production module, wherein the flame special effect production module simulates a flame effect through a particle system of a game engine;

[0060] 3. Collision detection unit, which performs collision detection based on the game engine and automatically triggers corresponding operations when the corresponding collision is triggered;

[0061] 4. VR interaction unit, used to realize the interaction between users and the system.

[0062] 5. Level sequence animation unit, the level sequence animation module is used to make animations and play animations when corresponding collisions are triggered.

[0063] 6. UI prompt unit. Users can use handle rays to interactively browse the 3DUI in the scene. The UI prompts in the start scene can provide the experiencer with operation help, experiment selection, exit experience, experiment operation prompts, etc. In short, the UI prompt unit is used to build various necessary UIs in the simulation process.

[0064] Each unit is described in detail below.

[0065] The first is the scene building unit, which requires the production of a chemical laboratory model and the chemical instruments and drugs needed for related chemical experiments. This embodiment uses junior high school chemical experiments as the interactive experience, so the middle school chemical laboratory and junior high school chemical experiments (sulfur combustion experiment, potassium permanganate oxygen production experiment, dust explosion experiment, and neutralization reaction experiment) are selected as references. The model types are as follows:

[0066]

[0067]

[0068] This embodiment uses C4D software to complete the production of the model, and the production process is as follows:

[0069] Model building: Use polygonal modeling methods to convert the basic model into an editable model, and then edit it in various ways such as moving and scaling points, lines, and surfaces to get the required low-level model, and then make high-precision modifications and adjustments through subdivision surfaces, alignment, smoothing, etc. During production, it is necessary to ensure that the object is highly restored, make materials, and add materials to get a high-precision model;

[0070] Material and texture production: refer to the real pictures to produce the materials and texture maps of multiple models in the scene in Adobe Photoshop 2018, and then import them into UE4 for material blueprint editing;

[0071] Scene construction: After making the model in C4D and assigning the material map, import the reference laboratory construction picture into UE4, and complete the splicing and placement of the model by moving and scaling. Then use UE4's material to modify and optimize the material, add lights and shadows, and adjust the placement;

[0072] Lighting optimization: There are 3 types of light sources in UE4, and the performance consumption from low to high is: directional light / parallel light < point light source < spotlight; this project mainly uses one or two spotlights to provide overall lighting, and then uses point light sources to fill in the light; all light sources are static light sources, and Csat Volumetric Shadow is turned off; finally, the post-production box is used to adjust the brightness and color of the overall environment;

[0073] Material optimization: plan the types of materials in the scene in advance; try to remove translucent materials to reduce consumption; reduce the use of decal materials; reduce material complexity.

[0074] Physics and collision optimization: Plan the physics and collision of the model, and classify interactive objects and non-interactive objects; cancel the simulated physics of all non-interactive objects, and choose Block or Overlap for collision. For chemical instruments and items for experimental interaction, set the corresponding physics and collision to prevent the erroneous effect of objects being knocked away after collision.

[0075] The special effects unit is introduced below. The existence of the special effects unit takes into account the combustion of matches, alcohol lamps, candles, and sulfur involved in the process of operating experimental interactions. Bubbles will appear in the experiment of producing oxygen from potassium permanganate. Dust explosions will occur in the experiment of operating dust explosions. These are necessary phenomena in the chemical experimental process.

[0076] The special effects produced in the special effects unit include flame effects, bubble effects and explosion effects.

[0077] The process of making flame effects: Use the particle system in UE4 to make flames, create a flame material ball, change the material's blending mode to Additive, and check the use of particle Sprite in the purpose; import the flame texture map and connect it to the B of the Multiply node, connect the A of the Multiply node to a three-dimensional node to set the color, and then connect the Multiply node to the self-luminous color of the material; hold down the keyboard 1 and click the left button to create a new one-dimensional node, change its value to 0.1. Connect it to the opacity of the material. The flame material is made. Then select the flame material made in the emitter material of the particle system, and modify the values ​​of required, generated, initial size, initial speed, etc. to get a flame particle effect.

[0078] The process of making bubble special effects: Create a new bubble material ball in UE4. The main production is to use particle Sprite, import the bubble texture and bubble normal texture, use Panner and texture coordinate nodes to modify the offset and coordinates of its texture, and make the bubble have a moving effect. The bubble material is completed. Then use the particle system in UE4 to make bubbles, select the bubble material in the emitter material of the particle system, and modify its required, generated, initial size, initial speed and other values ​​to get a bubble particle special effect.

[0079] Explosion special effect production process: Create a new explosion material ball in UE4. The main production is to use NiagaraSprites, import the explosion texture sequence map, modify the arrangement position of the texture map|, particle color, flame shape, modify its self-luminous color and opacity, and the explosion material is successfully produced. Create a Simple SpriteBurst template in the Niagara system, change the rendering material of Speite Renerer to the produced explosion material ball, divide the material into six rows and six columns, and the X and Y values ​​of the sub-image size are 6. Add a Sub UVAnimation in the particle update, change the playback range value to 0-35 frames, and change the playback time to 1s. Change the Life Cycke Mode in the Emitter State to System, and the explosion particles are produced. Then use the Niagara system in UE4 to produce the explosion effect, select the produced explosion material in the Niagara system renderer, and modify its particle generation, particle update and other values ​​to get an explosion particle special effect.

[0080] In the process of VR interaction, this embodiment mainly uses a large number of collision detections to realize the functions of object instrument medicine display and disappearance, instrument picking and releasing, instrument return, sequence animation, etc. to realize VR interaction, to complete a complete experimental operation process, and continuously improve and optimize functions to make VR interaction smoother and easier to use. Among them, this embodiment uses the virtual reality application template created by UnrealEngine version 4.27.2, and uses handle rays and handles to interact with the UI, which is conducive to the operation of the experiencer in the experiment.

[0081] Simulating the real experimental process requires hands-on operation of chemical experiments. Therefore, a VR interaction unit is needed. The VR interaction unit includes a picking and placing object module, a display and hiding module, and a homing module.

[0082] During the experimental interaction, the pick-up and place item module can use the handle to pick up and release chemical instruments, such as picking up and putting down matches, medicines, test tubes, etc., and also adds the effect of simulating the feedback vibration of the handle when touching an object.

[0083] The operation process is as follows: create a new blueprint interface, add pick-up and release functions, add input parameters to the pick-up function, and select the variable pin type as scene component. Create a new blueprint Actor, set the collision properties, and add object pick-up and release functions. Enter the left and right handle actions in the VRPawn blueprint. When the target is set to approach the object, determine whether the object has implemented the interface class method, and then execute the grab and release functions.

[0084] The blueprint logic diagram of grabbing and releasing is as follows Figure 1 As shown, the key blueprint nodes are as follows:

[0085] (1) Attach a component to a component

[0086] Attach this component to another scene component, optionally a named slot. This can be called on a component regardless of whether it is registered or not, the target is the scene component. Hold down the trigger to use this node to pick up an object and attach it to the handle.

[0087] (2) Separation from Actor

[0088] Detach the RootComponent of this Actor from all currently attached ScenneComponents, with the target being the Actor. The release trigger uses this node to detach the object that is attached to it, achieving the effect of releasing the object.

[0089] In order to make the experimental operation process smooth and reasonable, there will be some requirements for returning items to their original positions during the experimental operation, such as the opened medicine bottle caps need to be put back on the medicine, the small plastic bottles need to be connected to the soft rubber tube mouth and other detailed operations, so the item return function is made. The instrument return and collision trigger flow chart is as follows Figure 2 shown.

[0090] The operation process of the homing module is as follows: create a new Boolean variable guiwei, a transformation variable Taeget, a floating-point variable DeltaSeconds, and a floating-point variable Interp Speed. Call the event Tick to execute a connection to a sequence, and the sequence execution connects a branch. In the branch, the Condition connects to the newly created guiwei Boolean variable, and the branch True executes the connection to set the value of the variable DeltaSecond. The floating-point node connects to the floating point of the event Tick. Call the Set Actor Transformation node, connect the value of the variable DeltaSecond, and in the Set Actor Transformation node, connect the target to the Actor to be homed, obtain the Actor's transformation, transform T to interpolate, set the target transformation of the variable Taeget, the time after the last tick of the variable Delta Seconds, and the interpolation speed of the variable Interp Speed. In the overlapping event of the collision box, execute the connection type conversion to Yaoping1, check whether the collision is Yaoping1, and then execute the connection to set the value of the variable guiwei, and check Guiwei.

[0091] The blueprint logic diagram for instrument return is as follows: Figure 3 As shown, the key blueprint nodes are as follows:

[0092] (1) Setting Actor Transformation

[0093] Convert the target to the specified target, connect the new transformation, interpolate to the node through T, get the change from Actor to the world as the actual transformation, then use the variable transformation to set its transformation value to the target transformation, and then use the floating point variable to set the time and speed of its transformation.

[0094] (2)T interpolated to

[0095] Based on the distance from the current position, it attempts to achieve the target transformation; it provides a good sense of smoothness when tracking the position. This helps to make the object return process smoother during the experiment.

[0096] Setting the visibility of objects during the experimental operation is helpful to show some chemical phenomena of chemical experiments, such as the visibility of the flame of a match after it is lit, the visibility of medicine after it is picked up, the visibility of bubbles after the test tube is heated, etc. Therefore, a visibility module is needed.

[0097] The operation flow of the show / hide module is: call the event to start the execution event, execute the connection to set the Actor to be hidden in the game, check Boolean, and connect the target to hide the Actor; call the collision overlap event of the collision box, convert the type to Huochai_2, check whether the collision is Huochai_2, connect the Object category back to the Object Actor, use the delay node, call to set the Actor to be hidden in the game, and connect the target Actor. The flowchart of setting the hide and collision display is as follows Figure 4 shown.

[0098] The event starts executing the blueprint logic for hiding and collision detection display. Figure 5 As shown, the key blueprint nodes are as follows:

[0099] (1) Set the Actor to be hidden in the game

[0100] By setting the Actor to be hidden in the game, you can directly switch the node to display and hide the object. In the project, a large number of visible and hidden objects can be triggered by different collision detections to achieve the desired chemical experiment imagination and VR interaction effects.

[0101] The following is an introduction to the level sequence animation unit. Level sequence animation is used during the experimental operation to realize the experimental operation phenomenon, such as neutralization reaction color change and large plastic bottle explosion. Animation is used to well display the experimental phenomenon and improve fluency. Therefore, the level sequence animation unit is needed. Among them, the level sequence animation unit includes the neutralization reaction color change production module and the large plastic bottle explosion production module.

[0102] The production process of the neutralization reaction color change production module is as follows: create a new material, give the material a basic color, convert it into a parameter, and rename it to Color. Create a new material parameter set, add a vector parameter, name it Color, select the material ball, replace the basic color with the newly created material parameter set, and select Color as the parameter name. Create a new level sequence, drag the material parameter set in, add the Color attribute, modify its color value and set keyframes to get a material color change animation. Finally, use collision detection to play the solution color change animation after the experimental operation.

[0103] The production process of the large plastic bottle explosion production module is as follows: create a new blueprint Actor, add a scene component (Scene) and set the large plastic bottle static mesh as its subset, add a spline, add a function named fly, add a floating-point variable Distance, get the scene position and rotation node of the Scene, get the position at the distance along the spline, get the rotation at the distance along the spline, connect the target to the spline, use the floating-point variable Distance to control its position and rotation transformation, and select the world coordinate as the enumeration value. Select the variable Distance and check the public to cutscene to expose it to the Sequence. Connect the Fly function in the constructor to let the Fly function calculate from the beginning. Edit the spline and edit it into the required movement route. Create a new Sequence, add the variable Distance attribute and repeater event, keyframe the value of Distance, match the length of the event and the keyframe, call the Fly function in the event function, and check the activation event call in the editor. Finally, use collision detection to play the explosion and flying animation after the experimental operation.

[0104] Spline movement and collision detection play animation blueprint logic blueprint such as Figure 6 As shown, the key blueprint nodes are as follows:

[0105] (1) Get the position and rotation along the spline at the distance

[0106] Returns the position of the point in space at a given distance within the length of the spline, and the rotation of the corresponding spline here. Use the value of the floating-point variable to play keyframe transformations in the Sequence, thereby realizing an animation that transforms along the spline. It is helpful to adjust the route of the spline at any time, so as to adjust the motion trajectory and playback rate of the object.

[0107] (2) Play

[0108] Use collision detection triggers, determine the trigger conditions, and play the sequence player. The goal is to create a good explosion and knockback animation.

[0109] Through the above modules and units, a complete system for VR chemical laboratory simulation can be built, and then the simulation of sulfur combustion experiment, potassium permanganate oxygen production experiment, dust explosion experiment, neutralization reaction experiment and other experiments can be realized. The system block diagram of the VR chemical laboratory simulation system based on these experiments is as follows Figure 7 shown.

[0110] In one embodiment of the present invention, a chemical experiment simulation method based on virtual reality is provided, which is applied to the system as described above and comprises the following steps:

[0111] Build chemical laboratory models and chemical instrument models through scene building units. The chemical instrument models include alcohol lamps, test tubes, combustion spoons, gas collecting bottles, beakers, matches, sulfur, medicine spoons, glass pieces, and wide-mouth bottles.

[0112] During the chemical experiment, grab or place the chemical instrument model through the pick-up and place item module;

[0113] The collision detection unit performs collision detection based on the game engine, and triggers the corresponding chemical reaction particle special effects in the special effect unit after completing the correct collision detection operation;

[0114] By setting the Actor to be hidden in the game, you can directly switch the node to display and hide the object, and trigger the corresponding display and hiding through different collision detection.

[0115] The above steps are further illustrated below by specifically listing sulfur combustion experiments, potassium permanganate oxygen production experiments, dust explosion experiments, and neutralization reaction experiments.

[0116] like Figure 8 As shown, the sulfur combustion experiment is as follows:

[0117] (1) Remove the alcohol lamp cap and place it vertically on the table. This process is achieved through the pick-up and place object module.

[0118] (2) Light the match and the alcohol lamp. In this process, the pick-up and placement module is used to pick up the match, and the visible and invisible modules are used to make the match and the alcohol lamp invisible before and after lighting.

[0119] (3) Remove the cap of the jar containing sulfur and place it upside down on the table. This process is achieved through the pick-up and place item module.

[0120] (4) Take out a small amount of sulfur with a medicine spoon and cover the bottle cap. In this process, the position of the medicine spoon and the wide-mouth bottle is controlled by the picking mode item module, the visibility module triggers the visibility of sulfur after picking up sulfur through collision detection, and the open wide-mouth bottle cap is put back into the wide-mouth bottle through the homing module.

[0121] (5) Put sulfur into the combustion spoon. In this process, the medicine spoon and the combustion spoon are controlled by the pick-up and placement module, and then the visibility of the sulfur in the combustion spoon is triggered by the visibility module. The collision condition for triggering the visibility can be set as the collision between the medicine spoon and the combustion spoon.

[0122] (6) Place the burning spoon above the flame of the alcohol lamp to ignite the sulfur. This process is implemented through the display and hiding module, and the collision condition that triggers the display and hiding can be set as the collision between the burning spoon and the point above the flame of the alcohol lamp.

[0123] (7) Remove the glass sheet on the gas collecting bottle and place the combustion spoon into the gas collecting bottle. This process is achieved by using the pick-up and place item module to remove the glass sheet on the gas collecting bottle (the gas collecting bottle model includes the bottle body and the glass sheet) and to place the combustion spoon into the gas collecting bottle. The sulfur on the combustion spoon is burned by using the display and concealment module.

[0124] (8) Extinguish the burning sulfur. This process is achieved through the visible and invisible module.

[0125] like Fig. 9 As shown, the dust explosion test is as follows:

[0126] (1) Remove the lid of the wide-mouth bottle containing flour and turn it upside down on the table, and use a medicine spoon to take out the flour. This process is achieved by the pick-up and place module to take and place items, and the display module to make the flour on the medicine spoon visible.

[0127] (2) Put the flour into the small plastic bottle and cover it with a wide-mouth bottle cap. This process uses the pick-up and place module to realize the picking and placing of items, the revealing module to realize the appearance of the flour on the small plastic bottle, and the return module to realize the covering of the wide-mouth bottle cap.

[0128] (3) Light a match, then light a candle. This process uses the pick-up and place module to pick and place items, and uses the reveal module to make the flames on the match and candle visible.

[0129] (4) Connect the mouth of the small plastic bottle filled with flour to the mouth of the rubber tube. This process is achieved by the pick-up and place module to pick and place the item, and the return module to connect the small plastic bottle to the soft rubber tube.

[0130] (5) The candle is placed on the big plastic bottle and the small plastic bottle is covered on the latex tube. This process is achieved by the pick-and-place module.

[0131] (6) Rapid extrusion and inflation device. This process uses the level sequence animation unit to play the animation of the large plastic bottle explosion effect produced by the large plastic bottle explosion production module. The trigger time of the animation is determined based on the collision detection result.

[0132] The two experiments given above are sufficient to introduce the specific applications of specific units and modules in the experiments. The dust explosion experiment and neutralization reaction experiment given below only introduce the modules used in the process. The usage of the modules is similar to the two experimental examples given above.

[0133] like Fig.10 As shown, the dust explosion test is as follows:

[0134] (1) Check: Check the air tightness of the device by touching the test tube with the handle. Bubbles will come out of the test tube. After releasing the handle, a water column will form in the test tube. (Display module)

[0135] (2) Installation: Remove the lid of the wide-mouth bottle containing potassium permanganate and place it upside down on the table. (Pick up and place item module, display and hide module)

[0136] (3) Loading: Use a medicine spoon to take out a small amount of medicine and transfer it to a piece of paper. (Pick up and place item module, display and hide module)

[0137] (4) Loading: Cover the bottle cap, remove the rubber stopper and the catheter, take out the test tube and spread the medicine on the bottom of the test tube. (Pick up and place item module, display and hide module, return module)

[0138] (5) Fix: The mouth of the test tube is tilted downward and fixed on the iron frame. A small ball of cotton is placed in the mouth of the tube, and the mouth of the test tube is tightly plugged with a rubber stopper with a catheter. (Pick up and place object module, display module, return module)

[0139] (6) Point: Use a match to light the lamp and heat the test tube. (Pick up the item placement module, the visibility module)

[0140] (7) Collect: Use the gas collection bottle to collect gas and remove the water. (Pick up and place item module, show and hide module)

[0141] (8) Leave: Move the iron frame and the conduit out of the water. (Pick up the item placement module and the visibility module)

[0142] (9) Extinguish: Turn off the alcohol lamp. (Pick up and place item module, display and hide module, return module)

[0143] like Fig.11 As shown, the neutralization reaction experiment is as follows:

[0144] (1) Remove the bottle cap containing sodium hydroxide solution, turn it upside down on the table, and introduce the sodium hydroxide solution into the beaker. The corresponding animation is produced by the neutralization reaction color change production module and the corresponding animation is played based on the collision detected in this step. (Pick up and place item module, level sequence animation unit)

[0145] (2) Return the bottle of sodium hydroxide solution to its original position and put the cap on. (Pick-up and place item module, return module)

[0146] (3) Remove the lid of the jar containing the phenolphthalein solution, use the rubber-tipped dropper in front of the phenolphthalein solution to absorb the phenolphthalein solution, and cover the lid. (Pick up and place the item module, the display module, and the return module)

[0147] (4) Drip the solution from the rubber dropper vertically into the beaker. After dripping the solution, put the rubber dropper back to its original position. In this process, the neutralization reaction color change production module produces the corresponding animation and plays the corresponding animation based on the collision detected in this step. Note that the animation here may have a different color from the animation in step (1) depending on the specific situation. (Pick up and place item module, return module, level sequence animation unit)

[0148] (5) Remove the lid of the wide-mouth bottle containing the dilute hydrochloric acid solution, use the rubber-tipped dropper in front of the dilute hydrochloric acid solution to absorb the dilute hydrochloric acid solution and cover the lid. (Pick up and place item module, display and hide module)

[0149] (6) Pick up the glass rod and drip the solution from the rubber dropper vertically into the beaker, stirring while dripping. After dripping the solution, put the rubber dropper back in place. In this process, the neutralization reaction color change production module produces the corresponding animation and plays the corresponding animation based on the collision detected in this step. Note that the animation here may be different in color from the animation in step (1) and step (4) depending on the specific situation. (Pick up and place item module, show and hide module, level sequence animation unit)

[0150] (7) Use a glass rod to dip the reacted liquid onto the glass sheet on the clip. (Pick up and place item module, show and hide module)

[0151] (8) Use a match to light the alcohol lamp, and use a clamp to slightly bake the solution on the glass piece on the alcohol lamp. (Pick up and place item module, show and hide module)

[0152] In summary, the present invention builds a chemical laboratory model and a chemical instrument model through a scene building unit. During a chemical experiment, the chemical instrument model is grabbed or placed through a pick-up and place item module, and collision detection is performed through a collision detection unit. After completing the correct collision detection operation, the corresponding chemical reaction particle special effects in the special effect unit are triggered, and the Actor is set to hide in the game to directly switch nodes to display and hide objects, and the corresponding display and hiding are triggered through different collision detections. Then, many chemical experiments including sulfur combustion experiments, potassium permanganate oxygen production experiments, dust explosion experiments, and neutralization reaction experiments are simulated.

[0153] Those of ordinary skill in the art will appreciate that the units of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition of each example has been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0154] In the embodiments provided by the present invention, it should be understood that the division of units is only a logical function division, and there may be other division methods in actual implementation, for example, multiple units can be combined into one unit, one unit can be split into multiple units, or some features can be ignored, etc.

[0155] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0156] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-0nlyMemory), random access memory (RAM, RandomAccessMemory), mobile hard disk, magnetic disk or optical disk, etc., which can store program code.

[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A chemical experiment simulation system based on virtual reality, characterized in that: include: A scene building unit, using 3D modeling and animation software to build a chemical laboratory model and a chemical instrument model and import them into the game engine, wherein the chemical laboratory model includes a table and the chemical instrument model includes an alcohol lamp; The special effect unit includes a flame special effect production module, wherein the flame special effect production module simulates the flame effect through the particle system of the game engine; The collision detection unit performs collision detection based on the game engine and automatically triggers corresponding operations when the corresponding collision is triggered; The VR interaction unit includes a module for picking up and placing items and a display and hiding module. The module for picking up and placing items establishes grabbing events and releasing events, and uses a handle to pick up and release the chemical instrument. The display and hiding module displays and hides objects by setting the Actor to hide in the game and directly switches the node, and triggers the corresponding display and hiding through different collision detections.

2. A chemical experiment simulation system based on virtual reality according to claim 1, characterized in that: The operation process of the pick-up and place object module using the handle to pick up and release the chemical instrument is as follows: Create a new blueprint interface, add pick-up and release functions, add input parameters to the pick-up function, and select the variable pin type as the scene component; create a new blueprint Actor, set the collision properties, and add object pick-up and release functions; enter the left and right handle actions in the VRPawn blueprint, and when the target is set to approach the object, determine whether the object implements the method of the interface class, and then execute the grab and release functions.

3. A chemical experiment simulation system based on virtual reality according to claim 1, characterized in that: The specific operation of the display and concealment module is as follows: Call the event to start executing the event, execute the connection to set the Actor to be hidden in the game, check Boolean, and connect the target to hide the Actor; call the collision overlap event of the collision box, convert the type to Huochai_2, check whether the collision is Huochai_2, connect the Object category back to the Object Actor, use the delay node, call to set the Actor to be hidden in the game, and connect the target Actor.

4. A chemical experiment simulation system based on virtual reality according to claim 1, characterized in that: The VR interaction unit also includes a homing module, which is used to restore the chemical instrument. The manufacturing process is as follows: Create a new Boolean variable guiwei, a transformation variable Taeget, a floating-point variable Delta Seconds, and a floating-point variable InterpSpeed. Call the event Tick to execute a connection to a sequence. The sequence execution is connected to a branch. In the branch, Condition is connected to the newly created guiwei Boolean variable. The branch True execution is connected to set the value of the variable Delta Second. The floating-point node is connected to the floating point of the event Tick. Call the Set Actor Transformation node, connect and set the value of the variable Delta Second. In the Set Actor Transformation node, connect the target to the Actor to be relocated, get the Actor's transformation, transform T to interpolate, set the target transformation of the variable Taeget, the time since the last tick of the variable Delta Seconds, and the interpolation speed of the variable Interp Speed. In the overlap event of the collision box, execute the connection type conversion to Yaoping1, check whether the collision is Yaoping1, then execute the connection to set the value of the variable guiwei and check Guiwei.

5. A chemical experiment simulation system based on virtual reality according to claim 1, characterized in that: The flame special effect production module is used to produce flame special effects. The production process is as follows: Production of flame material: Use the particle system in UE4 to make flames, create a flame material ball, change the material's blending mode to Additive, and check Use particle Sprite in the purpose; import the flame texture map and connect it to the B of the Multiply node, connect the A of the Multiply node to a 3D node to set the color, and then connect the Multiply node to the self-luminous color of the material; create a new 1D node, modify its value and connect it to the opacity of the material; Select the prepared flame material in the emitter material of the particle system, modify the required, generated, initial size, initial speed and other values ​​to get a flame particle special effect.

6. A chemical experiment simulation system based on virtual reality according to claim 1, characterized in that: It also includes a level sequence animation unit, which is used to make animations and play animations when the corresponding collision is triggered. The level sequence animation unit includes a neutralization reaction color change production module, which is used to make material color change animations. The specific process is as follows: Create a new material, give it a base color, convert it to a parameter, and rename it to Color; Create a new material parameter set, add a vector parameter, name it Color, select the material ball, replace the base color with the newly created material parameter set, and select Color as the parameter name; Create a new level sequence, drag the material parameter set into it, add the Color attribute, modify its color value and set keyframes.

7. A chemical experiment simulation system based on virtual reality according to claim 1, characterized in that: It also includes a level sequence animation unit, which is used to make animations and play animations when a corresponding collision is triggered. The level sequence animation unit includes a plastic bottle explosion production module, which is used to make a plastic bottle explosion display animation. The specific process is as follows: Create a new blueprint Actor, add a scene component and set the large plastic bottle static mesh as its subset, add a spline, add a function named fly, add a floating-point variable Distance, get the Scene's Get Scene Position and Rotation nodes, get the distance position along the spline, get the distance rotation along the spline, connect the target to the spline, use the floating-point variable Distance to control its position and rotation transformation, and select the world coordinates from the enumeration value; Select the variable Distance and check Public to Cutscene to expose it to Sequence. Connect the Fly function in the constructor to make the Fly function calculate from the beginning. Edit the spline to the required motion path; Create a new Sequence, add the variable Distance property and repeater event, set a keyframe for the Distance value, match the event and keyframe lengths, call the Fly function in the event function, and check the activation event call in the editor; Use collision detection to implement the explosion and knockback animation after the experimental operation.

8. A chemical experiment simulation method based on virtual reality, characterized in that: The system applied to any one of claims 1 to 7 comprises the following steps: Build chemical laboratory models and chemical instrument models through scene building units. The chemical instrument models include alcohol lamps, test tubes, combustion spoons, gas collecting bottles, beakers, matches, sulfur, medicine spoons, glass pieces, and wide-mouth bottles. During the chemical experiment, grab or place the chemical instrument model through the pick-up and place item module; The collision detection unit performs collision detection based on the game engine, and triggers the corresponding chemical reaction particle special effects in the special effect unit after completing the correct collision detection operation; By setting the Actor to be hidden in the game, you can directly switch the node to display and hide the object, and trigger the corresponding display and hiding through different collision detection.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the virtual reality-based chemical experiment simulation method according to claim 8.

10. A processor, characterized in that: The processor is used to run a program, wherein when the program is run, the virtual reality-based chemical experiment simulation method according to claim 8 is executed.

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