具有立方体旋转的OpenGL和GLM问题

Question

我正在从http://learnopengl.com学习OpenGL，我有一个基于本章坐标系统的转换问题…我想要渲染像这个Movie这样的东西，但是我有一个类似Movie2的东西，它在5秒内回到了屏幕上。很抱歉有很多链接，但我认为用视频来展示这个更容易。这是我的渲染循环:

const auto projection = glm::perspectiveFov(glm::radians(45.0f), 800.0f, 600.0f, 0.1f, 100.0f);
const auto view = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, -3.0f));
while (!glfwWindowShouldClose(window))
{
processInput(window);
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
flatColorShader->bind();
flatColorShader->setMat4("u_Projection", projection);
flatColorShader->setMat4("u_View", view);
auto model = glm::mat4(1.0f);
model = glm::rotate(model, static_cast<float>(glfwGetTime()) * glm::radians(50.0f), glm::vec3(0.5f, 1.0f, 0.0f));
flatColorShader->setMat4("u_Model", model);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(vao);
glfwSwapBuffers(window);
glfwPollEvents();
}

Vaertex材质:

#version 460 core
layout (location = 0) in vec3 a_Pos;
layout (location = 1) in vec2 a_TexCoord;
out vec2 v_TexCoord;
uniform mat4 u_Projection;
uniform mat4 u_Model;
uniform mat4 u_View;
void main()
{
v_TexCoord = vec2(a_TexCoord.x, 1.0f - a_TexCoord.y);
gl_Position = u_Projection * u_Model * u_View * vec4(a_Pos, 1.0);
}

And Fragment shader:

#version 460 core
in vec2 v_TexCoord;
out vec4 color;
uniform sampler2D u_Texture;
void main()
{
color = texture(u_Texture, v_TexCoord);
}

我想这是模型矩阵的问题，但我不知道是什么。有人能帮我解决这个问题吗?

Answer 1

顶点着色器中的顶点转换顺序不正确:

gl_Position = u_Projection * u_Model * u_View * vec4(a_Pos, 1.0);

gl_Position = u_Projection * u_View * u_Model * vec4(a_Pos, 1.0);

顺序很重要，因为矩阵乘法是不可交换的。