在 OpenGL 中渲染三角形网格时出现问题

Question

我正在尝试使用标准 VBO/VAO/EBO 技术在 OpenGL 和 C++ 中渲染由三角形组成的方形网格，但由于某种原因，这些东西无法正确渲染。

我首先根据 gridSideLength 生成网格的顶点和索引

int gridSideLength= 16; // any power of 2
    unsigned int gridVBO, gridVAO, gridEBO;

    const uint32_t verticesCount = (gridSideLength + 1) * (gridSideLength + 1);
    const uint32_t indicesCount = gridSideLength * gridSideLength* 2;

    std::vector<glm::vec3> vertices(verticesCount);
    std::vector<glm::vec3> indices(indicesCount);

    // populate vertices
    uint32_t idx = 0;
    for (float i = -(gridSideLength / 2); i <= (gridSideLength / 2); ++i) {
        for (float j = -(gridSideLength / 2); j <= (gridSideLength / 2); ++j) {
            vertices[idx] = glm::vec3((float)j, 0.0f, (float)i);
            idx++;

        }
    }

    // populate indices with clockwise winding
    idx = 0;
    for (int i = 0; i < gridSideLength; ++i) {
        int row1 = i * (gridSideLength + 1);
        int row2 = (i + 1) * (gridSideLength + 1);

        for (int j = 0; j < gridSideLength; ++j) {
            indices[idx++] = glm::uvec3(row1 + j, row1 + j + 1, row2 + j + 1);
            indices[idx++] = glm::uvec3(row1 + j, row2 + j + 1, row2 + j);

        }
    }

据我所知，通过打印值，这会生成正确的顶点和索引。

接下来，设置 VBO、VAO 和 EBO 对象

    // bind grid VBO, VAO, and EBO
    glGenBuffers(1, &gridVBO);
    glBindBuffer(GL_ARRAY_BUFFER, gridVBO);
    glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(vertices[0]), &vertices[0], GL_STATIC_DRAW);

    glGenVertexArrays(1, &gridVAO);
    glBindVertexArray(gridVAO);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0);

    glGenBuffers(1, &gridEBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gridEBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(indices[0]), &indices[0], GL_STATIC_DRAW);

这对我来说看起来还不错，我可以用它来渲染一些东西，但我不知道。

最后，我的渲染循环：

while (glfwWindowShouldClose(window) == false) 
{
    glm::mat4 model = glm::mat4(1.0f);
    glm::mat4 view = camera.CalculateViewMatrix();
    glm::mat4 projection = glm::perspective(glm::radians(camera.getZoom()), (float)SCREEN_WIDTH / (float)SCREEN_HEIGHT, 0.1f, 100.0f);

    // ...
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glClearColor(0.05f, 0.05f, 0.05f, 1.0f);
        
    glBindVertexArray(m_GridVAO);
    glDrawElements(GL_TRIANGLES, indices.size() * 3, GL_UNSIGNED_INT, 0);
}

不幸的是，我得到的只是一条线，除了把头撞在墙上之外，我不知道从这里该去哪里。有什么明显的错误吗？感谢您的帮助！

Answer 1

顶点索引必须是整数值：

std::vector<glm::vec3> indices(indicesCount);

std::vector<glm::uvec3> indices(indicesCount);