2015-10-27 180 views
1

我目前正在尝试使用java和LWJGL 3库的openGL进行编程。我试图实现透视投影矩阵,但在当前状态下,模型不会显示出来。透视投影矩阵不工作openGL

public static Matrix4f pespectiveProjectionMatrix(float screenWidth, float screenHeight, float FOV, float near, float far) { 
    Matrix4f result = identity(); 

    float aspectRatio = screenWidth/screenHeight; 

    result.elements[0 + 0 * 4] = (float) ((1/tan(toRadians(FOV/2)))/aspectRatio); 
    result.elements[1 + 1 * 4] = (float) (1/tan(FOV/2)); 
    result.elements[2 + 2 * 4] = -(far + near)/(far - near); 
    result.elements[2 + 3 * 4] = -1; 
    result.elements[3 + 2 * 4] = -(2 * far * near)/(far - near); 
    result.elements[3 + 3 * 4] = 0; 

    return result; 
} 

Matrix4f类提供了包含4 * 4矩阵的“elements”数组。该identity()方法返回一个简单的单位矩阵。

这是当前矩阵的样子:

0.75  |0.0  |0.0  |0.0  | 
0.0  |0.6173696|0.0  |0.0  | 
0.0  |0.0  |-1.0001999|-1.0  | 
0.0  |0.0  |-0.20002 |0.0  | 

顶点着色器:

#version 400 core 

in vec3 position; 
in vec2 textureCoords; 

out vec2 pass_textureCoords; 

uniform mat4 transformationMatrix; 
uniform mat4 projectionMatrix; 

void main(void) { 

    gl_Position = projectionMatrix * transformationMatrix * vec4(position, 1.0); 
    pass_textureCoords = textureCoords; 

} 

渲染:

Matrix4f projectionMatrix = Matrix4f.pespectiveProjectionMatrix(800.0f, 600.0f, 90.0f, 0.1f, 1000.0f); //Creates the projection matrix (screenWidth, screenHeight, FOV, near cutting plane, far cutting plane) 

shader.loadTransformationMatrix(transformationMatrix); //loads the transformationMatrix 
shader.loadProjectionMatrix(projectionMatrix); //Load the projection matrix in a uniform variable 
+0

你有,你实际调用LWJGL程序代码? –

+0

已编辑,我插入了主要代码 –

+0

FOV是什么单位?你使用它两次来计算'tan()'。一旦你把它转换成弧度,你第二次没有。另外,它看起来像是按照行优先顺序构建投影矩阵。矩阵通常在OpenGL中使用,它们需要按照列主要顺序存储。 –

回答

0

我的问题是,我忘了视界转换第二行的弧度:

result.elements[1 + 1 * 4] = (float) (1/tan(FOV/2)); 

应该

result.elements[1 + 1 * 4] = (float) (1/tan(toRadians(FOV/2)));