在LWJGL3中使用HDR地图

Question

我目前正在使用LWJGL3并构建一个简单的Skybox。我想让skybox接收一个HDR文件，一个等长方形的地图。我可以得到一个skybox运行与PNG与PNG解码器，但不确定它将如何与HDR文件。据我所知，STB（在C++中）允许在程序中上传HDR文件，LWJGL3也支持STB。

我如何创建一个支持机顶盒和HDR文件的loadTexture函数？

编辑：我要把我的进展发布给任何人，这样任何人都可以看到我一直在做什么。

public int loadCubeMap(String textureFile) throws IOException {

 int texID = glGenTextures();
 glBindTexture(GL_TEXTURE_2D, texID);

 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

 ByteBuffer imageBuffer;
 IntBuffer w = BufferUtils.createIntBuffer(1);
 IntBuffer h = BufferUtils.createIntBuffer(1);
 IntBuffer comp = BufferUtils.createIntBuffer(1);
 ByteBuffer image;

 imageBuffer = IOUtil.ioResourceToByteBuffer(textureFile, 8 * 1024);

 if (!stbi_info_from_memory(imageBuffer, w, h, comp))
     throw new IOException("Failed to read image information: " + stbi_failure_reason());

 image = stbi_load_from_memory(imageBuffer, w, h, comp, 3);

 if (image == null)
     throw new IOException("Failed to load image: " + stbi_failure_reason());
 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, w.get(0), h.get(0), 0, GL_RGB, GL_UNSIGNED_BYTE, image);

 stbi_image_free(image);

 return texID; }

private static final float SIZE = 500f;

private static final float[] VERTICES = {        
    -SIZE,  SIZE, -SIZE,
    -SIZE, -SIZE, -SIZE,
    SIZE, -SIZE, -SIZE,
     SIZE, -SIZE, -SIZE,
     SIZE,  SIZE, -SIZE,
    -SIZE,  SIZE, -SIZE,

    -SIZE, -SIZE,  SIZE,
    -SIZE, -SIZE, -SIZE,
    -SIZE,  SIZE, -SIZE,
    -SIZE,  SIZE, -SIZE,
    -SIZE,  SIZE,  SIZE,
    -SIZE, -SIZE,  SIZE,

     SIZE, -SIZE, -SIZE,
     SIZE, -SIZE,  SIZE,
     SIZE,  SIZE,  SIZE,
     SIZE,  SIZE,  SIZE,
     SIZE,  SIZE, -SIZE,
     SIZE, -SIZE, -SIZE,

    -SIZE, -SIZE,  SIZE,
    -SIZE,  SIZE,  SIZE,
     SIZE,  SIZE,  SIZE,
     SIZE,  SIZE,  SIZE,
     SIZE, -SIZE,  SIZE,
    -SIZE, -SIZE,  SIZE,

    -SIZE,  SIZE, -SIZE,
     SIZE,  SIZE, -SIZE,
     SIZE,  SIZE,  SIZE,
     SIZE,  SIZE,  SIZE,
    -SIZE,  SIZE,  SIZE,
    -SIZE,  SIZE, -SIZE,

    -SIZE, -SIZE, -SIZE,
    -SIZE, -SIZE,  SIZE,
     SIZE, -SIZE, -SIZE,
     SIZE, -SIZE, -SIZE,
    -SIZE, -SIZE,  SIZE,
     SIZE, -SIZE,  SIZE
};

private RawModel cube;
private int skyboxTexture;
private SkyboxShader shader;

public SkyboxRenderer(Loader loader, Matrix4f projectionMatrix) throws IOException {
    cube = loader.loadToVAO(VERTICES, 3);
    skyboxTexture = loader.loadCubeMap("res/newport_loft.hdr");
    shader = new SkyboxShader();
    shader.start();
    shader.loadProjectionMatrix(projectionMatrix);
    shader.connectTextureUnits();
    shader.stop();
    }

public void render(Camera camera) {
    shader.start();
    shader.loadViewMatrix(camera);
    GL30.glBindVertexArray(cube.getVaoID());
    GL20.glEnableVertexAttribArray(0);

    GL11.glBindTexture(GL13.GL_TEXTURE_CUBE_MAP, skyboxTexture);
    GL11.glDrawArrays(GL11.GL_TRIANGLES, 0, cube.getVertexCount());
    GL20.glDisableVertexAttribArray(0);
    GL30.glBindVertexArray(0);
    shader.stop();
    }
}

#version 330 core 

layout (location = 0) in vec3 aPos;

out vec3 WorldPos;

uniform mat4 projection; 
uniform mat4 view;

void main() {
    WorldPos = aPos;  
    gl_Position =  projection * view * vec4(WorldPos, 1.0); }

#version 330 core
out vec4 FragColor;
in vec3 WorldPos;

uniform sampler2D equirectangularMap;

const vec2 invAtan = vec2(0.1591, 0.3183);
vec2 SampleSphericalMap(vec3 v)
{
    vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
    uv *= invAtan;
    uv += 0.5;
    return uv;
}

void main()
{       
    vec2 uv = SampleSphericalMap(normalize(WorldPos));
    vec3 color = texture(equirectangularMap, uv).rgb;

    FragColor = vec4(color, 1.0);
}

着色器代码在ThinMatrix教程的帮助下工作得很好。

公共类SkyboxShader扩展ShaderProgram{

private static final String VERTEX_FILE = "src/skybox/cubemap.vs";
private static final String FRAGMENT_FILE = "src/skybox/cubemap.fs";

private int location_projectionMatrix;
private int location_viewMatrix;

private int location_equirectangularMap;

public SkyboxShader() {
    super(VERTEX_FILE, FRAGMENT_FILE);
}

public void loadProjectionMatrix(Matrix4f matrix){
    super.loadMatrix(location_projectionMatrix, matrix);
}

public void loadViewMatrix(Camera camera){
    Matrix4f matrix = Maths.createViewMatrix(camera);
    super.loadMatrix(location_viewMatrix, matrix);
}

@Override
protected void getAllUniformLocations() {
    location_projectionMatrix = super.getUniformLocation("projection");
    location_viewMatrix = super.getUniformLocation("view");
    location_equirectangularMap = super.getUniformLocation("equirectangularMap");
}

@Override
protected void bindAttributes() {
    super.bindAttribute(0, "aPos");
}

public void connectTextureUnits() {
    super.loadInt(location_equirectangularMap, 0);
} }

我在skybox渲染器中初始化loadCubeMap函数以及文件名，然后在主渲染器类中初始化skybox渲染器。

编辑：

所以我试着重新设计它。image变量被更改为浮动缓冲区，现在接受带有stbi_loadf_from_memory的image。还是一个但是很困惑，没想到HDR地图会这么困惑。

public int loadCubeMap(String textureFile) throws IOException {

         int texID = glGenTextures();
         //glActiveTexture(GL11.GL_TEXTURE);
         glBindTexture(GL_TEXTURE_2D, texID);

         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

         ByteBuffer imageBuffer;
         IntBuffer w = BufferUtils.createIntBuffer(1);
         IntBuffer h = BufferUtils.createIntBuffer(1);
         IntBuffer comp = BufferUtils.createIntBuffer(1);
         FloatBuffer image;

         imageBuffer = IOUtil.ioResourceToByteBuffer(textureFile, 8 * 1024);

         if (!stbi_info_from_memory(imageBuffer, w, h, comp))
             throw new IOException("Failed to read image information: " + stbi_failure_reason());

         image = stbi_loadf_from_memory(imageBuffer, w, h, comp, 3);



         if (image == null)
             throw new IOException("Failed to load image: " + stbi_failure_reason());
         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16, w.get(0), h.get(0), 0, GL_RGB16, GL_FLOAT, image);

         stbi_image_free(image);

         return texID;

Answer 1

应该使用stbi_load_from_memory()，而不是stbi_loadf_from_memory()，这是读取HDR文件的函数。STB还包含stbi_is_hdr_from_memory()等函数，这些函数允许您确保缓冲区包含HDR映像。

注意stbi_load_from_memory()返回一个包含纹理的floatbuffer。

此外，您应该修改对glteximage2d()的调用：

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