Tutorial_505_EyeDomeLighting

The source file containing the main() function:

/********************************************************************
 * 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_points.h>
#include <easy3d/renderer/renderer.h>
#include <easy3d/util/resource.h>
#include <easy3d/util/initializer.h>
 
 
using namespace easy3d;
 
// This example shows how to
//      - render a point cloud without normal information (but still be
//        able to perceive the depth) using the Eye Dome Lighting technique.
 
 
int main(int argc, char **argv) {
    // initialize Easy3D.
    initialize();
 
    const std::string file = resource::directory() + "/data/bunny.bin";
 
    // create the viewer.
    TutorialEyeDomeLighting viewer(EXAMPLE_TITLE);
 
    // Read the point cloud from a known file.
    Model *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_points_drawable("vertices");
    drawable->set_uniform_coloring(vec4(0.6f, 0.6f, 1.0f, 1.0f));
    drawable->set_point_size(5.0f);
 
    // run the viewer
    return viewer.run();
}
 

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_EYE_DOME_LIGHTING_H
#define EASY3D_TUTORIAL_EYE_DOME_LIGHTING_H
 
#include <easy3d/viewer/viewer.h>
 
 
// This class renders a point cloud without normal information. 
// It uses the Eye Dome Lighting technique to improve depth perception.
 
namespace easy3d {
    class EyeDomeLighting;
}
 
class TutorialEyeDomeLighting : public easy3d::Viewer
{
public:
    explicit TutorialEyeDomeLighting(const std::string& title = "");
    ~TutorialEyeDomeLighting() override;
 
protected:
    bool key_press_event(int key, int modifiers) override;
 
    void draw() const override;
 
private:
    easy3d::EyeDomeLighting* edl_;
    bool edl_enabled_;
};
 
 
#endif // EASY3D_TUTORIAL_EYE_DOME_LIGHTING_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/point_cloud.h>
#include <easy3d/renderer/opengl.h>
#include <easy3d/renderer/drawable_points.h>
#include <easy3d/renderer/camera.h>
#include <easy3d/renderer/shader_manager.h>
#include <easy3d/renderer/shader_program.h>
#include <easy3d/renderer/eye_dome_lighting.h>
#include <easy3d/renderer/renderer.h>
#include <easy3d/util/setting.h>
 
 
using namespace easy3d;
 
TutorialEyeDomeLighting::TutorialEyeDomeLighting(const std::string& title) : Viewer(title) {
    camera()->setUpVector(vec3(0, 1, 0));
    camera()->setViewDirection(vec3(0, 0, -1));
    camera_->showEntireScene();
 
    edl_ = new EyeDomeLighting(camera());
    edl_enabled_ = true;
 
    usage_string_ =
            "---------- Eye Dome Lighting usage --------- \n"
            "Press key 'space' to toggle Eye Dome Lighting\n"
            "-------------------------------------------- \n";
}
 
 
TutorialEyeDomeLighting::~TutorialEyeDomeLighting() {
    delete edl_;
 
    // Not needed: it will be called in the destructor of the base class
    //Viewer::cleanup();
}
 
 
bool TutorialEyeDomeLighting::key_press_event(int key, int modifiers) {
    if (key == KEY_SPACE) {
        edl_enabled_ = !edl_enabled_;
        std::cout << "Eye Dome Lighting " << (edl_enabled_ ? "enabled" : "disabled") << std::endl;
        update();
        return true;
    }
    else
        return Viewer::key_press_event(key, modifiers);
}
 
 
void TutorialEyeDomeLighting::draw() const {
    if (!current_model()) {
        return;
    }
 
    if (edl_enabled_) {
        const mat4& MVP = camera_->modelViewProjectionMatrix();
        // camera position is defined in world coordinate system.
        const vec3& wCamPos = camera_->position();
        // it can also be computed as follows:
        //const vec3& wCamPos = invMV * vec4(0, 0, 0, 1);
        const mat4& MV = camera_->modelViewMatrix();
        const vec4& wLightPos = inverse(MV) * setting::light_position;
 
        ShaderProgram* program = ShaderManager::get_program("points/points_plain_color");
        if (!program) {
            std::vector<ShaderProgram::Attribute> attributes;
            attributes.emplace_back(ShaderProgram::Attribute(ShaderProgram::POSITION, "vtx_position"));
            attributes.emplace_back(ShaderProgram::Attribute(ShaderProgram::COLOR, "vtx_color"));
            attributes.emplace_back(ShaderProgram::Attribute(ShaderProgram::NORMAL, "vtx_normal"));
            program = ShaderManager::create_program_from_files("points/points_plain_color", attributes);
        }
        if (!program)
            return;
 
        auto drawable = current_model()->renderer()->get_points_drawable("vertices");
        float point_size = drawable->point_size();
        glPointSize(point_size);
 
        edl_->begin();
        program->bind();
        program->set_uniform("MVP", MVP);
        program->set_uniform("wLightPos", wLightPos);
        program->set_uniform("wCamPos", wCamPos);
        program->set_uniform("lighting", drawable->normal_buffer());
        program->set_uniform("per_vertex_color", drawable->coloring_method() != State::UNIFORM_COLOR && drawable->color_buffer());
        program->set_uniform("default_color", drawable->color());
        drawable->gl_draw();
 
        program->release();
        edl_->end();
    }
    else
        Viewer::draw();
}