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;
    }
}