[netCDF #WRU-342191]: NetCDF VIsualization in c++

Hello,

I'm not sure how you'd be able to render the netCDF data using OpenGL; my 
OpenGL is quite a bit out of date, and I'm unfamiliar with VTK.  I know it's an 
open source program, published by KitWare, you might be able take a look at 
their 3D rendering code to see what they do with the data once they've imported 
it from the netCDF storage layer.

Sorry I can't provide more immediate help, hopefully this will point you in the 
right direction,

-Ward

> how  can i render netcdf data to opengl viewport similar to what vtk does
> int ncid;
> int status =
> nc_open("C:/Users/---/Desktop/BOLTgui/BOLT/OR_ABI-L2-ACMF-M6_G18_s20230880050215_e20230880059523_c20230880100259.nc",
> NC_NOWRITE, &ncid);
> 
> if (status != NC_NOERR) {
> std::cout << "Error opening file: " << nc_strerror(status) <<
> std::endl;
> return -1;
> }
> 
> int ndims;
> status = nc_inq_ndims(ncid, &ndims);
> if (status != NC_NOERR) {
> std::cout << "Error inquiring about number of dimensions: " <<
> nc_strerror(status) << std::endl;
> return -1;
> }
> 
> std::cout << "Number of dimensions: " << ndims << std::endl;
> 
> for (int i = 0; i < ndims; i++) {
> char dimname[NC_MAX_NAME + 1];
> size_t dimlen;
> 
> status = nc_inq_dim(ncid, i, dimname, &dimlen);
> if (status != NC_NOERR) {
> std::cout << "Error inquiring about dimension: " <<
> nc_strerror(status) << std::endl;
> return -1;
> }
> 
> std::cout << "Dimension name: " << dimname << ", length: " <<
> dimlen << std::endl;
> }
> 
> status = nc_close(ncid);
> if (status != NC_NOERR) {
> std::cout << "Error closing file: " << nc_strerror(status) <<
> std::endl;
> return -1;
> }
> 
> while (window.isOpen()) {
> sf::Event event;
> while (window.pollEvent(event)) {
> if (event.type == sf::Event::Closed) {
> window.close();
> break;
> }
> 
> else if (event.type == sf::Event::MouseWheelScrolled) {
> zoomLevel += event.mouseWheelScroll.delta * 0.1f;
> }
> else if (event.type == sf::Event::MouseWheelScrolled) {
> zoomLevel += event.mouseWheelScroll.delta * 0.1f;
> }
> if (event.type == sf::Event::MouseButtonPressed) {
> if (event.mouseButton.button == sf::Mouse::Left) {
> bool isOnTopPanel = sf::Mouse::getPosition(window).y <=
> WIDGET_PANEL_HEIGHT;
> bool isOnBottomPanel = sf::Mouse::getPosition(window).y
> >= WINDOW_HEIGHT - WIDGET_PANEL_HEIGHT;
> if (!isOnTopPanel && !isOnBottomPanel) {
> leftButtonPressed = true;
> previousMousePosition =
> sf::Mouse::getPosition(window);
> 
> }
> }
> }
> else if (event.type == sf::Event::MouseButtonReleased) {
> if (event.mouseButton.button == sf::Mouse::Left) {
> leftButtonPressed = false;
> }
> }
> }
> 
> 
> now = std::chrono::system_clock::now();
> currentTime = std::chrono::system_clock::to_time_t(now);
> localtime_s(&localTime, &currentTime);
> 
> dateStream.str(""); // Clear the stream before updating
> dateStream << std::put_time(&localTime, "%m/%d/%Y");
> dateString = dateStream.str();
> text16.setString(dateString);
> 
> timeStream.str(""); // Clear the stream before updating
> timeStream << std::put_time(&localTime, "%I:%M:%S %p");
> timeString = timeStream.str();
> text17.setString(timeString);
> slider.handleEvent(event, window);
> 
> bool isPopupWindowOpen = false;
> sf::Mutex mutex;
> if (event.type == sf::Event::MouseButtonPressed) {
> if (event.mouseButton.button == sf::Mouse::Left) {
> bool isOnTopPanel = sf::Mouse::getPosition(window).y <=
> WIDGET_PANEL_HEIGHT;
> bool isOnBottomPanel = sf::Mouse::getPosition(window).y >=
> WINDOW_HEIGHT - WIDGET_PANEL_HEIGHT;
> if (!isOnTopPanel && !isOnBottomPanel) {
> leftButtonPressed = true;
> previousMousePosition = sf::Mouse::getPosition(window);
> }
> 
> // Convert the mouse position from screen coordinates to
> window coordinates
> sf::Vector2f mousePosition =
> window.mapPixelToCoords(sf::Mouse::getPosition(window));
> 
> // Soundings Popup Window
> sf::FloatRect buttonBounds2(button.getPosition().x,
> button.getPosition().y, button.getSize().x, button.getSize().y);
> if (buttonBounds2.contains(mousePosition.x,
> mousePosition.y))
> {
> sf::Lock lock(mutex);
> if (!isPopupWindowOpen)
> {
> isPopupWindowOpen = true;
> Soundings soundings;
> soundings.run();
> isPopupWindowOpen = false;
> }
> }
> // GOES Popup Window
> sf::FloatRect buttonBounds(button5.getPosition().x,
> button5.getPosition().y, button5.getSize().x, button5.getSize().y);
> if (buttonBounds.contains(mousePosition.x, mousePosition.y))
> {
> sf::Lock lock(mutex);
> if (!isPopupWindowOpen)
> {
> isPopupWindowOpen = true;
> GOES GOES;
> GOES.run();
> isPopupWindowOpen = false;
> }
> }
> }
> }
> 
> 
> // Add the code to fix the earth model from going to the bottom
> left when resizing the window
> // Check if the window size has changed
> if (window.getSize().x != window.getView().getSize().x ||
> window.getSize().y != window.getView().getSize().y)
> {
> // Update the view to the new window size
> glMatrixMode(GL_PROJECTION);
> glLoadIdentity();
> gluPerspective(45.0f, (GLfloat)window.getSize().x /
> (GLfloat)window.getSize().y, 0.1f, 100.0f);
> 
> // Set up the viewport to the new window size
> glViewport(0, 0, window.getSize().x, window.getSize().y);
> }
> 
> 
> glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
> 
> // Set up the modelview matrix and apply the rotation
> glMatrixMode(GL_MODELVIEW);
> glLoadIdentity();
> gluLookAt(0.0f, 0.0f, 3.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f);
> glTranslatef(0.0f, 0.0f, -zoomLevel); // Add this line to translate
> in the z-axis
> 
> glRotatef(rotationAngleX, 0.0f, 1.0f, 0.0f); // Rotate around the
> Y-axis
> glRotatef(rotationAngleY, 1.0f, 0.0f, 0.0f); // Rotate around the
> X-axis
> 
> // Enable texture and bind it
> glEnable(GL_TEXTURE_2D);
> glBindTexture(GL_TEXTURE_2D, textureId);
> 
> 
> // Draw the model
> glBegin(GL_TRIANGLES);
> for (size_t i = 0; i < indices.size(); i++) {
> glTexCoord2f(texcoords[2 * i], texcoords[2 * i + 1]);
> glVertex3f(vertices[3 * i], vertices[3 * i + 1], vertices[3 * i
> + 2]);
> }
> if (leftButtonPressed) {
> // Calculate the mouse movement since the last frame
> sf::Vector2i currentMousePosition =
> sf::Mouse::getPosition(window);
> sf::Vector2i mouseMovement = currentMousePosition -
> previousMousePosition;
> previousMousePosition = currentMousePosition;
> 
> // Calculate the rotation angles based on the mouse movement
> rotationAngleX += mouseMovement.x * 0.5f;
> rotationAngleY += mouseMovement.y * 0.5f;
> 
> }
> 
> glEnd();
> 
> // Disable texture
> glDisable(GL_TEXTURE_2D);
> drawShapefileObjects(allObjects);
> 
> glColor3f(1.0f, 1.0f, 1.0f);
> 
> window.resetGLStates();
> 
> glDisable(GL_DEPTH_TEST);
> 
> 


Ticket Details
===================
Ticket ID: WRU-342191
Department: Support netCDF
Priority: Normal
Status: Closed
===================
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