Xingchen Ming [email protected]
Ming Xu [email protected]
Geng Yang [email protected]
- Introduction
- Software Architectural Design
- Interface Descriptions
- Testing and Evaluation
- Conclusions
- Future Work
- Author Contributions
The Solar System is a cross-platform software that has 3D simulation of the Solar System and night sky in real-time. All parameters and calculations are based on real data published by NASA. Users can find key information, position and time data for each planets. Our model is a great tool to help children and astronomy enthusiast know deeply to the real Solar System.
- Adjust view and zoom in/out.
- Adjust time speed to fast forward/rewind.
- Select particular planet and display its characteristics.
- Highlight a selected planet and hide the others.
- Customize parameters(radius, mass, etc.) of selected objects.
- The selected planet can be dragged along its orbit.
- Select particular time to see status of Solar System.
- Update status using concurrency.
- Exception handling.
- Qt 5.10.1
- OpenGL 4.1
- freeglut 3.0.0
The graphical interface consists of two parts. The left one is the widget for displaying solar system, and the right one is for user manipulation.
C++ 11 threads is employed for concurrency. To update the status of each astronomical object simultaneously and quickly, multithreading is needed and each thread is responsible for updating one object.
void RenderingWidget::updatePosition(){
std::vector<std::thread> threads;
for (auto it : solarSystem->getObjects())
threads.push_back(std::thread(&AstronmicalObject::update,it,timeSpeed));
for_each(threads.begin(),threads.end(),mem_fn(&std::thread::join));
}
- Users are allowed to modidy basic parameters. New parameters should be positive numbers within a range and will be examined in the way of regular expression, or a dialog would show error information and suggest users to re-enter.
- All the files that need parsing are added into Qt resource and can be accessed with relative path in code, which helps avoid invalid absolute paths.
The operating system and software compiler/library version(s) tested are as follows.
- Operating system: macOS 10.14.1
- Compiler version: clang-1000.10.44.4
- Qt version: 5.11.2
- QMake version: 3.1
- OpenGL version: 4.1
- freeglut version: 3.0.0
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Functions
- Click Start/Pause button to start/stop simulation.
- Select an object and click Highlight button, only selected object and its characteristics shown on screen.
- Check Time box to stop and change date and time, the status of object would change accordingly.
- Adjust Time Speed slider, planets’ revolution and rotation speed would be accelerated or slowed down. Positive time speed would yield counterclockwise revolution while negative time speed would yield clockwise revolution.
- Check Data box, modify selected object’s parameters and press confirm botton or return, object’s attribute would be modified simultaneously.(Object’s size would change with radius changed etc). Invalid inputs would yield a warning and wouldn’t be accepted. Reset button help reset object’s attribute.
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Intereactions
- Perspective changes when scroll mouse wheel or press left button and move mouse.
- Perspective rotates 90 degrees with double click.
- Time stops when click one of the objects, and Data box shows basic information of the selected object.
- Object moves counterclockwise or clockwise by dragging it directly, other objects moves correspondingly, and time changes based on objects’ position.
This software can be built on Linux, macOS and Windows, the instructions are as follows.
- Clone the repository.
$ git clone [email protected]:ENGN2912B-2018/GPU-A.git
- If build on CCV, please load the following modules.
$ moudle load qt/5.10.1
$ moudle load freeglut/3.0.0
- Generate MakeFile and Compile.
Note: the build/ directory should be in the same directory with GPU-A/.
$ mkdir build
$ cd build
$ qmake ../GPU-A/SolarSystem.pro
$ make
- Run the executable in terminal or open it directly in
build/
open SolarSystem.app
- Reasonable and logical class hierarchy design.
- An reasonable and concise GUI.
- Interaction using mouse.
- Zoom in/out with mouse wheel.
- Double click to switch the view horizontally and vertically.
- Click on background, adjust view with left button.
- Click on abstronomical object, drag it along orbit with left button.
- 3D display of the system.
- Highlight the selected astronomical object with introduction and hide the others.
- Customize date and time to switch to corresponding status.
- Customize time speed to fast foward/rewind the simulation.
- Customize parameter of selected astronomical object and verify the input.
Most objectives have been achieved as proposed. There still exists a challenge unresolved, the simulation of changes brought by customized parameters. For example, when the revolution speed of Earth increases greatly, the Earth should run away from Sun with the speed decreasing gradually, and then run towards its original orbit and recover original status.
- The software has provided APIs for customizing parameters of astronomical objects, which aims to simulate the real scene in solar system when when the property of objects changes suddenly.
- Render the objects with enhanced textures, as the user zooms into a planet.
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Ming Xu designed class hierarchy and completed computing the status of astronomical objects.
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Geng Yang designed the GUI, completed basic interactions (e.g. adjust view, set date and timespeed) and 3D display.
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Xingchen Ming was responsible for parameter configuration, exception handling and interaction between user and astronomical objects.