[Solved] Graphics Lab7-Skybox

Lab 7

Setting up a skybox

Change the Texture.h as follows

Add the following methods

GLuint loadCubemap(std::vector<std::string> faces);

GLint getTexHandler() { return textureHandler; }

Addthe following method to the texture.cpp

GLuint Texture::loadCubemap(std::vector<std::string> faces)

{

glGenTextures(1, &textureHandler);

glBindTexture(GL_TEXTURE_CUBE_MAP, textureHandler);

int width, height, nrChannels;

for (unsigned int i = 0; i < faces.size(); i++)

{

unsigned char *data = stbi_load(faces[i].c_str(), &width, &height, &nrChannels, 0);

if (data)

{

glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i,

0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data

);

stbi_image_free(data);

}

else

{

std::cout << Cubemap texture failed to load at path: << faces[i] << std::endl;

stbi_image_free(data);

}

}

glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);

return textureHandler;

}

In the maingame.h add the following

void Skybox();

GLuint skyboxVAO, skyboxVBO, cubemapTexture;

vector<std::string> faces;

Texture skybox;

Shader shaderSkybox;

In the maingame add the following to the init method

vector<std::string> faces

{

..\res\skybox\right.jpg,

..\res\skybox\left.jpg,

..\res\skybox\top.jpg,

..\res\skybox\bottom.jpg,

..\res\skybox\front.jpg,

..\res\skybox\back.jpg

};

cubemapTexture = skybox.loadCubemap(faces); //Load the cubemap using faces into cubemapTextures

float skyboxVertices[] = {

// positions

-6.0f, 6.0f, -6.0f,

-6.0f, -6.0f, -6.0f,

6.0f, -6.0f, -6.0f,

6.0f, -6.0f, -6.0f,

6.0f, 6.0f, -6.0f,

-6.0f, 6.0f, -6.0f,

-6.0f, -6.0f, 6.0f,

-6.0f, -6.0f, -6.0f,

-6.0f, 6.0f, -6.0f,

-6.0f, 6.0f, -6.0f,

-6.0f, 6.0f, 6.0f,

-6.0f, -6.0f, 6.0f,

6.0f, -6.0f, -6.0f,

6.0f, -6.0f, 6.0f,

6.0f, 6.0f, 6.0f,

6.0f, 6.0f, 6.0f,

6.0f, 6.0f, -6.0f,

6.0f, -6.0f, -6.0f,

-6.0f, -6.0f, 6.0f,

-6.0f, 6.0f, 6.0f,

6.0f, 6.0f, 6.0f,

6.0f, 6.0f, 6.0f,

6.0f, -6.0f, 6.0f,

-6.0f, -6.0f, 6.0f,

-6.0f, 6.0f, -6.0f,

6.0f, 6.0f, -6.0f,

6.0f, 6.0f, 6.0f,

6.0f, 6.0f, 6.0f,

-6.0f, 6.0f, 6.0f,

-6.0f, 6.0f, -6.0f,

-6.0f, -6.0f, -6.0f,

-6.0f, -6.0f, 6.0f,

6.0f, -6.0f, -6.0f,

6.0f, -6.0f, -6.0f,

-6.0f, -6.0f, 6.0f,

6.0f, -6.0f, 6.0f

};

//use openGL functionality to generate & bind data into buffers

glGenVertexArrays(1, &skyboxVAO);

glGenBuffers(1, &skyboxVBO);

glBindVertexArray(skyboxVAO);

glBindBuffer(GL_ARRAY_BUFFER, skyboxVBO);

glBufferData(GL_ARRAY_BUFFER, sizeof(skyboxVertices), &skyboxVertices, GL_STATIC_DRAW);

glEnableVertexAttribArray(0);

glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);

}

Add the following method

void MainGame::Skybox()

{

glDepthFunc(GL_LEQUAL); // change depth function so depth test passes when values are equal to depth buffers content

shaderSkybox.Bind();

shaderSkybox.setInt(skybox, 0);

//view = glm::mat4(glm::mat3(camera.GetViewMatrix())); // remove translation from the view matrix

shaderSkybox.setMat4(view, myCamera.GetView());

shaderSkybox.setMat4(projection, myCamera.GetProjection());

// skybox cube

glBindVertexArray(skyboxVAO);

glActiveTexture(GL_TEXTURE0);

glBindTexture(GL_TEXTURE_CUBE_MAP, cubemapTexture);

glDrawArrays(GL_TRIANGLES, 0, 36);

glBindVertexArray(0);

glDepthFunc(GL_LESS); // set depth function back to default

}

TODO..

Initialise the skybox shader

Draw the skybox

Run the code, find and fix the error!