Question

我有Kinect的屏幕空间坐标。我需要为我的opengl相机从kinect获取世界空间坐标；或者我需要将相机放置在与Kinect相同的位置，以便可以看到从Kinect获得的点。我想我需要世界坐标w.r.t.我的opengl相机也可以对我正在绘制的其他对象进行碰撞检测。如何获得此ScreenspaceToWorld映射？

我使用this答案作为参考，但是我没有Kinect的位置和方向来计算“视图和投影”矩阵。

编辑：

Kinect FOV

我需要能够在与Kinect相同的坐标空间中渲染对象。为了做到这一点，我使用了使用这些值的投影矩阵：

近平面：0.01f
平面：1700.0f
水平FOV ：60.0f
垂直视野：45.0f
相机位置 ：( 0.0f，2.0f，3.0f）
相机方向：（0.0f，2.0f，-3.0f）

使用这些值，我看不到任何呈现的对象。这是我的渲染代码：

GameRenderer::GameRenderer()
{
    tracker = new GestureTracker();
    tracker->init();
    tracker->startGestureDetection();
}

bool GameRenderer::Init(int argc, char* argv[])
{        
    GLfloat points[] = { 0.0f, 0.5f, 0.0f, 0.5f, -0.5f, 0.0f, -0.5f, -0.5f, 0.0f };
    GLfloat point[] = { 0.0f, 0.0f, 0.0f };
    glGenBuffers(1, &m_vbo);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);

    glBufferData(GL_ARRAY_BUFFER, sizeof(points), points, GL_DYNAMIC_DRAW);
    // vao
    glGenVertexArrays(1, &m_vao);
    glBindVertexArray(m_vao);
    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);


    const char *vertex_shader = "#version 410\n"
                                "in vec3 vp;"
                                "uniform mat4 model_matrix;"
                                "uniform mat4 view_matrix;"
                                "uniform mat4 projection_matrix;"
                                "void main () {"
                                "  gl_Position = projection_matrix * view_matrix * model_matrix * vec4(vp, 1.0);"
                                "}";

    const char *fragment_shader = "#version 410\n"
                                  "out vec4 frag_colour;"
                                  "void main () {"
                                  "  frag_colour = vec4(0.0f, 0.5f, 1.0f, 1.0f);"
                                  "}";

    m_vert_shader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(m_vert_shader, 1, &vertex_shader, NULL);
    glCompileShader(m_vert_shader);
    int params = -1;
    glGetShaderiv( m_vert_shader, GL_COMPILE_STATUS, &params );
    if ( GL_TRUE != params ) {
        ShaderLog(m_vert_shader);
        return 1;
    }
    m_frag_shader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(m_frag_shader, 1, &fragment_shader, NULL);
    glCompileShader(m_frag_shader);
    params = -1;
    glGetShaderiv( m_frag_shader, GL_COMPILE_STATUS, &params );
    if ( GL_TRUE != params ) {
        ShaderLog(m_frag_shader);
        return 1;
    }
    m_shader_program = glCreateProgram();
    glAttachShader(m_shader_program, m_frag_shader);
    glAttachShader(m_shader_program, m_vert_shader);
    glLinkProgram(m_shader_program);

    this->m_model_matrix = glm::mat4(1.0f);
    m_model_matrix = glm::scale(m_model_matrix, glm::vec3(4.0f));
    // m_model_matrix = glm::rotate(m_model_matrix, glm::radians(10.0f), glm::vec3(0.0f));
    m_model_matrix = glm::translate(m_model_matrix, glm::vec3(0.0f));
    this->m_view_matrix = glm::mat4(1.0f);
    this->m_proj_matrix = glm::mat4(1.0f);

    GLuint model_mat_location = glGetUniformLocation(this->m_shader_program, "model_matrix");
    glUseProgram(this->m_shader_program);
    glUniformMatrix4fv(model_mat_location, 1, GL_FALSE, glm::value_ptr(this->m_model_matrix));
    return 1;
}

void GameRenderer::Draw(Camera& camera)
{
    auto hands = tracker->getHands();

    if(hands.size()) {
        Point3f coordinates = hands[0].getHandPosition();
        glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
        GLfloat hand_coordinate[3] = { coordinates.x, coordinates.y, coordinates.z };
        std::cout << coordinates.x << " " << coordinates.y << " " << coordinates.z << std::endl;
        // glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 3, hand_coordinate, GL_DYNAMIC_DRAW);
        this->m_model_matrix = glm::mat4(1.0f);
        m_model_matrix = glm::scale(m_model_matrix, glm::vec3(10.0f));
        m_model_matrix = glm::translate(m_model_matrix, glm::vec3(coordinates.x, coordinates.y, coordinates.z));
        glUseProgram(this->m_shader_program);
        GLuint loc = glGetUniformLocation(this->m_shader_program, "model_matrix");
        glUniformMatrix4fv(loc, 1, GL_FALSE, glm::value_ptr(this->m_model_matrix));
        glUseProgram(0);
    }
    this->m_view_matrix = camera.GetViewMatrix();
    this->m_proj_matrix = glm::perspective(glm::radians(camera.GetFieldOfView()),
                                           60.0f/45.0f, camera.GetNearPlane(), camera.GetFarPlane());


    GLuint view_mat_location = glGetUniformLocation(this->m_shader_program, "view_matrix");
    glUseProgram(this->m_shader_program);
    glUniformMatrix4fv(view_mat_location, 1, GL_FALSE, glm::value_ptr(this->m_view_matrix));

    GLuint proj_mat_location = glGetUniformLocation(this->m_shader_program, "projection_matrix");
    glUseProgram(this->m_shader_program);
    glUniformMatrix4fv(proj_mat_location, 1, GL_FALSE, glm::value_ptr(this->m_proj_matrix));

    CheckGLError();
    glUseProgram(m_shader_program);
    glBindVertexArray(m_vao);
    glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
    // glPointSize(50.0f);
    glDrawArrays(GL_TRIANGLES, 0, 3);
    glUseProgram(0);
    CheckGLError();
}

Kinect深度框的坐标值（这些是Kinect跟踪的手坐标）是：

x y z
-75.1628 136.374 650.176
-73.7582 141.239 665.259
-69.9152 148.691 702.163
-67.1218 151.315 723.226
-64.4887 153.013 745.074
-62.3365 153.783 767.393
-62.3365 153.783 767.393
-60.1887 152.979 789.881
-57.9948 150.762 812.395
-55.8624 146.575 834.187
-56.2673 133.543 873.035

当Kinect检测到“手”时，我的几何图形（现在是三角形）将停止渲染，尽管它之前已渲染（因为它是在原点）。

需要在我的视图/投影矩阵或代码中进行哪些纠正才能与Kinect的空间相同？

使用Nuitrack的Kinect相机放置位置

0 个答案: