Example: opengl_skybox_example

Demo of MRPT SkyBox.

See: Tutorial: 3D scenes

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2024, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#include <mrpt/core/format.h>
#include <mrpt/gui/CDisplayWindow3D.h>
#include <mrpt/img/TColor.h>
#include <mrpt/opengl/CAxis.h>
#include <mrpt/opengl/CBox.h>
#include <mrpt/opengl/CSkyBox.h>
#include <mrpt/opengl/CSphere.h>
#include <mrpt/opengl/stock_objects.h>
#include <mrpt/system/filesystem.h>

#include <iostream>
#include <thread>

/* Download and extract the sky box textures, so we dont need to add them
  to the already too large MRPT git repo:

CloudyLightRays/
├── CloudyLightRaysBack.jpg
├── CloudyLightRaysDown.jpg
├── CloudyLightRaysFront.jpg
├── CloudyLightRaysLeft.jpg
├── CloudyLightRaysRight.jpg
├── CloudyLightRaysUp.jpg
├── LICENSE.txt
└── README.txt
 */
const char* urlZip = "https://mrpt.github.io/mvsim-models/skyboxes/SunSet.zip";
const char* textureDir = "./SunSet/";
const char* textureFilePattern = "./SunSet/SunSet%s.jpg";

void downloadTextures()
{
  if (mrpt::system::directoryExists(textureDir)) return;  // already there

  int ret = ::system(mrpt::format("wget %s -O texture.zip", urlZip).c_str());
  if (ret) THROW_EXCEPTION("Error invoking wget to download the texture package.");

  ret = ::system("unzip texture.zip");
  if (ret) THROW_EXCEPTION("Error invoking unzip to extract the texture package.");
}

// ------------------------------------------------------
//              TestSkyBox
// ------------------------------------------------------
void TestSkyBox()
{
  downloadTextures();

  mrpt::gui::CDisplayWindow3D win("Example of MRPT skybox", 800, 600);

  mrpt::opengl::Scene::Ptr& theScene = win.get3DSceneAndLock();

  // Create the 3D scene:
  // ------------------------------------------------------

  // Create the SkyBox:
  {
    using mrpt::opengl::CUBE_TEXTURE_FACE;

    auto sb = mrpt::opengl::CSkyBox::Create();

    std::vector<std::pair<CUBE_TEXTURE_FACE, const char*>> faceImages = {
        { CUBE_TEXTURE_FACE::FRONT, "Front"},
        {  CUBE_TEXTURE_FACE::BACK,  "Back"},
        {CUBE_TEXTURE_FACE::BOTTOM,  "Down"},
        {   CUBE_TEXTURE_FACE::TOP,    "Up"},
        {  CUBE_TEXTURE_FACE::LEFT,  "Left"},
        { CUBE_TEXTURE_FACE::RIGHT, "Right"},
    };

    for (const auto& p : faceImages)
    {
      const auto fil = mrpt::format(textureFilePattern, p.second);
      std::cout << "Loading face texture: " << fil << std::endl;

      sb->assignImage(p.first, mrpt::img::CImage::LoadFromFile(fil));
    }

    theScene->insert(sb);
  }

  {
    auto obj = mrpt::opengl::CAxis::Create();
    obj->setFrequency(5);
    obj->enableTickMarks();
    obj->setAxisLimits(-10, -10, -10, 10, 10, 10);
    theScene->insert(obj);
  }

  theScene->insert(mrpt::opengl::stock_objects::CornerXYZ(3.0));

  {
    auto obj = mrpt::opengl::CBox::Create();
    obj->setWireframe(false);
    obj->setColor(1, 0, 0);
    obj->setLineWidth(3.0);
    obj->setPose(mrpt::math::TPose3D(1, 2, 3, 0.2, 0.3, 0.1));
    theScene->insert(obj);
  }

  {
    auto obj = mrpt::opengl::CSphere::Create();
    obj->setColor(0, 0, 1);
    obj->setRadius(0.3f);
    obj->setLocation(0, -2, 0);
    obj->setName("ball_1");
    theScene->insert(obj);
  }

  // IMPORTANT!!! IF NOT UNLOCKED, THE WINDOW WILL NOT BE UPDATED!
  win.unlockAccess3DScene();

  // change camera parasm:
  win.setCameraAzimuthDeg(40.0f);
  win.setCameraElevationDeg(10.0f);
  win.setCameraZoom(4.0f);
  win.setFOV(70.0f);

  // Update window:
  win.forceRepaint();

  win.waitForKey();
}

// ------------------------------------------------------
//                      MAIN
// ------------------------------------------------------
int main()
{
  try
  {
    TestSkyBox();
    return 0;
  }
  catch (const std::exception& e)
  {
    std::cerr << "MRPT error: " << mrpt::exception_to_str(e) << std::endl;
    return -1;
  }
}