readme.md

立方体贴图

天空盒

GL_TEXTURE_CUBE_MAP包含六个纹理

纹理目标	方位	简称
GL_TEXTURE_CUBE_MAP_POSITIVE_X	右	px
GL_TEXTURE_CUBE_MAP_NEGATIVE_X	左	ny
GL_TEXTURE_CUBE_MAP_POSITIVE_Y	上	py
GL_TEXTURE_CUBE_MAP_NEGATIVE_Y	下	ny
GL_TEXTURE_CUBE_MAP_POSITIVE_Z	后	pz
GL_TEXTURE_CUBE_MAP_NEGATIVE_Z	前	nz

绘制天空盒

vertex shader

#version 330 core
layout(location = 0) in vec3 Position;
out vec3 outTexCoord;
uniform mat4 view;
uniform mat4 projection;

void main() {
	outTexCoord = Position;
	vec4 pos = projection * view * vec4(Position, 1.0);
	gl_Position = pos;
}

fragment shader

#version 330 core
layout(location = 0) in vec3 Position;
layout(location = 1) in vec3 Normal;
layout(location = 2) in vec2 TexCoords;
out vec2 outTexCoord;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main() {
  gl_Position = projection * view * model * vec4(Position, 1.0f);
  outTexCoord = TexCoords;
}

// 绘制天空盒
glDepthFunc(GL_LEQUAL);
glDisable(GL_DEPTH_TEST);

skyboxShader.use();
skyboxShader.setMat4("view", view);
skyboxShader.setMat4("projection", projection);

glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_CUBE_MAP, cubemapTexture);
glBindVertexArray(skyboxGeometry.VAO);
glDrawElements(GL_TRIANGLES, skyboxGeometry.indices.size(), GL_UNSIGNED_INT, 0);

glBindVertexArray(0);
glDepthFunc(GL_LESS);
glEnable(GL_DEPTH_TEST);

移除平移

view = glm::mat4(glm::mat3(camera.GetViewMatrix())); // 移除平移分量

// 绘制其它物体时恢复
view = camera.GetViewMatrix();

参考

https://learnopengl-cn.github.io/04%20Advanced%20OpenGL/06%20Cubemaps/