Tutorial_502_HardShadow/main.cpp

This example shows how to renders a scene with hard shadow using the shadow map technique.

The header file of the viewer class:

/********************************************************************
 * Copyright (C) 2015 Liangliang Nan <liangliang.nan@gmail.com>
 * https://3d.bk.tudelft.nl/liangliang/
 *
 * This file is part of Easy3D. If it is useful in your research/work,
 * I would be grateful if you show your appreciation by citing it:
 * ------------------------------------------------------------------
 *      Liangliang Nan.
 *      Easy3D: a lightweight, easy-to-use, and efficient C++ library
 *      for processing and rendering 3D data.
 *      Journal of Open Source Software, 6(64), 3255, 2021.
 * ------------------------------------------------------------------
 *
 * Easy3D is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 3
 * as published by the Free Software Foundation.
 *
 * Easy3D is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 ********************************************************************/
 
#ifndef EASY3D_TUTORIAL_HARD_SHADOW_H
#define EASY3D_TUTORIAL_HARD_SHADOW_H
 
#include <easy3d/viewer/viewer.h>
 
 
// This class renders a scene with hard shadow using the shadow map technique.
 
namespace easy3d {
    class Shadow;
}
 
class TutorialHardShadow : public easy3d::Viewer
{
public:
    explicit TutorialHardShadow(const std::string& title = "");
    ~TutorialHardShadow() override;
 
protected:
    bool key_press_event(int key, int modifiers) override;
    void draw() const override;
 
private:
    easy3d::Shadow* shadow_;
    bool            shadow_enabled_;
};
 
 
#endif // EASY3D_TUTORIAL_HARD_SHADOW_H

The source file of the viewer class:

/********************************************************************
 * Copyright (C) 2015 Liangliang Nan <liangliang.nan@gmail.com>
 * https://3d.bk.tudelft.nl/liangliang/
 *
 * This file is part of Easy3D. If it is useful in your research/work,
 * I would be grateful if you show your appreciation by citing it:
 * ------------------------------------------------------------------
 *      Liangliang Nan.
 *      Easy3D: a lightweight, easy-to-use, and efficient C++ library
 *      for processing and rendering 3D data.
 *      Journal of Open Source Software, 6(64), 3255, 2021.
 * ------------------------------------------------------------------
 *
 * Easy3D is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 3
 * as published by the Free Software Foundation.
 *
 * Easy3D is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 ********************************************************************/
 
#include "viewer.h"
#include <easy3d/core/surface_mesh.h>
#include <easy3d/renderer/drawable_triangles.h>
#include <easy3d/renderer/shadow.h>
#include <easy3d/renderer/camera.h>
#include <easy3d/renderer/renderer.h>
 
 
using namespace easy3d;
 
// \cond
 
TutorialHardShadow::TutorialHardShadow(const std::string& title) : Viewer(title) {
    camera()->setUpVector(vec3(0, 1, 0));
    camera()->setViewDirection(vec3(0, 0, 1));
 
    shadow_ = new Shadow(camera());
    shadow_->set_virtual_background_color(background_color());
    shadow_enabled_ = true;
 
    hint_ = "Press 'space' to switch on/off shadowing";
}
 
 
TutorialHardShadow::~TutorialHardShadow() {
    delete shadow_;
 
    // Not needed: it will be called in the destructor of the base class
    //Viewer::cleanup();
}
 
 
bool TutorialHardShadow::key_press_event(int key, int modifiers) {
    if (key == KEY_SPACE) {
        shadow_enabled_ = !shadow_enabled_;
        update();
        return true;
    }
    else
        return Viewer::key_press_event(key, modifiers);
}
 
 
void TutorialHardShadow::draw() const {
    if (!current_model()) {
        return;
    }
 
    std::vector<TrianglesDrawable*> surfaces;
    for (auto m : models_) {
        for (auto d : m->renderer()->triangles_drawables()) {
            surfaces.push_back(d.get());
        }
    }
    if (shadow_enabled_)
        shadow_->draw(surfaces);
    else
        Viewer::draw();
}
 
// \endcond

/********************************************************************
 * Copyright (C) 2015 Liangliang Nan <liangliang.nan@gmail.com>
 * https://3d.bk.tudelft.nl/liangliang/
 *
 * This file is part of Easy3D. If it is useful in your research/work,
 * I would be grateful if you show your appreciation by citing it:
 * ------------------------------------------------------------------
 *      Liangliang Nan.
 *      Easy3D: a lightweight, easy-to-use, and efficient C++ library
 *      for processing and rendering 3D data.
 *      Journal of Open Source Software, 6(64), 3255, 2021.
 * ------------------------------------------------------------------
 *
 * Easy3D is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 3
 * as published by the Free Software Foundation.
 *
 * Easy3D is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 ********************************************************************/
 
#include "viewer.h"
#include <easy3d/core/model.h>
#include <easy3d/renderer/drawable_triangles.h>
#include <easy3d/renderer/renderer.h>
#include <easy3d/util/resource.h>
#include <easy3d/util/initializer.h>
 
using namespace easy3d;
 
 
int main(int argc, char **argv) {
    // initialize Easy3D.
    initialize();
 
    const std::string file = resource::directory() + "/data/room.obj";
 
    // create the viewer.
    TutorialHardShadow viewer(EXAMPLE_TITLE);
 
    auto model = viewer.add_model(file, true);
    if (!model) {
        LOG(ERROR) << "failed to load model. Please make sure the file exists and format is correct.";
        return EXIT_FAILURE;
    }
 
    auto drawable = model->renderer()->get_triangles_drawable("faces");
    drawable->set_uniform_coloring(vec4(0.9f, 0.9f, 0.9f, 1.0f));
    drawable->set_smooth_shading(true);
 
    // run the viewer
    return viewer.run();
}