透視投影OpenGL和計算着色器

Question

我下面這個網站了解射線使用計算着色器跟蹤：https://github.com/LWJGL/lwjgl3-wiki/wiki/2.6.1.-Ray-tracing-with-OpenGL-Compute-Shaders-%28Part-I%29

我的問題，該教程詳細的程序，以獲得透視投影。我想我正確地遵循了他的步驟，但是我得到了錯誤的結果，我相信我在矩陣計算中犯了一個錯誤。

我對透視代碼projection-

//Getting the perspective projection using glm::perspective 
glm::mat4 projection = glm::perspective(60.0f, 1024.0f/768.0f, 1.0f, 2.0f); 

//My Camera Position 
glm::vec3 camPos=glm::vec3(3.0, 2.0, 7.0); 

//My View matrix using glm::lookAt 
glm::mat4 view = glm::lookAt(camPos, glm::vec3(0.0, 0.5, 0.0),glm::vec3(0.0, 1.0, 0.0)); 

//Calculating inverse of the view*projection 
glm::mat4 inv = glm::inverse(view*projection); 

//Calculating the rays from camera position to the corners of the frustum as detailed in the site. 
glm::vec4 ray00=glm::vec4(-1, -1, 0, 1) * inv; 
ray00 /= ray00.w; 
ray00 -= glm::vec4(camPos,1.0); 

glm::vec4 ray10 = glm::vec4(+1, -1, 0, 1) * inv; 
ray10 /= ray10.w; 
ray10 -= glm::vec4(camPos,1.0); 

glm::vec4 ray01=glm::vec4(-1, 1, 0, 1) * inv; 
ray01 /= ray01.w; 
ray01 -= glm::vec4(camPos,1.0); 

glm::vec4 ray11 = glm::vec4(+1, +1, 0, 1) * inv; 
ray11 /= ray11.w; 
ray11 -= glm::vec4(camPos,1.0); 

上述tranformations的結果：[！[此處輸入圖像的描述] [1]]

[1]

作爲附加信息，我打電話給我的計算着色器使用

//Dispatch Shaders. 
glDispatchCompute ((GLuint)1024.0/16, (GLuint)768.0f/8 , 1); 

我也通過值到着色器使用

//Querying the location for ray00 and assigning the value. Similarly for the rest 
GLuint ray00Id = glGetUniformLocation(computeS, "ray00"); 
glUniform3f(ray00Id, ray00.x, ray00.y, ray00.z); 

GLuint ray01Id = glGetUniformLocation(computeS, "ray01"); 
glUniform3f(ray01Id, ray01.x, ray01.y, ray01.z); 

GLuint ray10Id = glGetUniformLocation(computeS, "ray10"); 
glUniform3f(ray10Id, ray10.x, ray10.y, ray10.z); 

GLuint ray11Id = glGetUniformLocation(computeS, "ray11"); 
glUniform3f(ray11Id, ray11.x, ray11.y, ray11.z); 

GLuint camId = glGetUniformLocation(computeS, "eye"); 
glUniform3f(camId, camPos.x, camPos.y, camPos.z); 

更新回答關於derhass的建議。

我的形象現在看起來像： Latest Image

Answer 1

GLM的庫使用標準的OpenGL矩陣慣例，這意味着矩陣在頭腦裏的乘法順序Matrix * Vector創建。所以下面的代碼是錯誤的：

//Calculating inverse of the view*projection 
glm::mat4 inv = glm::inverse(view*projection); 

視圖矩陣和投影矩陣（從世界空間到眼睛空間變換）的（從眼睛空間變換到剪裁空間）的組成projection * view，因爲你把不view * projection它（它將在視圖之前應用投影）。