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Opengl-三角赢了';不渲染? 我试图通过C++在OpenGL中使用VBOS渲染三角形。_C++_Opengl_Graphics_Vbo_Vao - Fatal编程技术网

Opengl-三角赢了';不渲染? 我试图通过C++在OpenGL中使用VBOS渲染三角形。

Opengl-三角赢了';不渲染? 我试图通过C++在OpenGL中使用VBOS渲染三角形。,c++,opengl,graphics,vbo,vao,C++,Opengl,Graphics,Vbo,Vao,首先,我确定了我的变量: CBuint _vao; CBuint _vbo; CBuint _ebo; struct Vertex { CBfloat position[3]; }; 然后,我设置每个顶点的位置以形成一个几何三角形: Vertex v[3]; v[0].position[0] = 0.5f; v[0].position[1] = 0.5f; v[0].position[2] = 0.0f; v[1].position[0] = 0.5f; v[1].position

首先,我确定了我的变量:

CBuint _vao;
CBuint _vbo;
CBuint _ebo;

struct Vertex
{
    CBfloat position[3];
};
然后,我设置每个顶点的位置以形成一个几何三角形:

Vertex v[3];
v[0].position[0] = 0.5f;
v[0].position[1] = 0.5f;
v[0].position[2] = 0.0f;

v[1].position[0] = 0.5f;
v[1].position[1] = -0.5f;
v[1].position[2] = 0.0f;

v[2].position[0] = -0.5f;
v[2].position[1] = -0.5f;
v[2].position[2] = 0.0f;
很简单,对吧? 然后,我宣布我的EBO/IBO指数:

unsigned short i[] =
{
    0, 1, 2
};
现在我有了缓冲所需的所有属性数据,我绑定了VAO和VBO:

// Generate vertex elements
glGenVertexArrays(1, &_vao);
glGenBuffers(1, &_vbo);
glGenBuffers(1, &_ebo);

// VAO
glBindVertexArray(_vao);

// VBO
glBindBuffer(GL_ARRAY_BUFFER, _vbo);    
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex) * 9, &v, GL_STATIC_DRAW);

// EBO
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _ebo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(unsigned short) * 3, &i, GL_STATIC_DRAW);

// Location 0 - Positions
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), BUFFER_OFFSET(0));

glBindVertexArray(0);
接下来,我呈现它们:

glBindVertexArray(_vao);
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_SHORT, 0);
glBindVertexArray(0);
然后我使用顶点着色器:

#version 330 core

// Vertex attributes
layout(location = 0) in vec3 position;

// Node parses
out vec3 Fragpos;

// Uniforms
uniform mat4 model;
uniform mat4 projection;
uniform mat4 view;

// Vertex loop
void main()
{
    gl_Position = projection * view * model * vec4(position, 1.0f);   
    Fragpos = vec3(model * vec4(position, 1.0f));
}
CBuint  _u_model;

mat4    _model;
vec3    _position;
vec4    _rotation;
vec3    _scale;
只需计算模型位置以及摄影机视图。片段着色器同样非常简单:

#version 330 core

// Node parses
out vec4 color;
in vec3 Fragpos;

// Camera data
uniform vec3    view_loc;

// Global uniforms
uniform struct GLOBAL
{
    float   ambient_coefficient;
    vec3    ambient_colour;
} _global;

// Main loop
void main(void)
{
    color = vec4(1.0, 1.0, 1.0, 1.0);
}
制服工作得非常好,因为我在以前的项目中使用了此着色器代码。那么问题出在哪里呢?三角形根本不渲染。我想不出是什么原因造成的,有什么想法吗

编辑:为了缩小范围,我还使用这些变量来处理从顶点着色器解析到的模型矩阵:

#version 330 core

// Vertex attributes
layout(location = 0) in vec3 position;

// Node parses
out vec3 Fragpos;

// Uniforms
uniform mat4 model;
uniform mat4 projection;
uniform mat4 view;

// Vertex loop
void main()
{
    gl_Position = projection * view * model * vec4(position, 1.0f);   
    Fragpos = vec3(model * vec4(position, 1.0f));
}
CBuint  _u_model;

mat4    _model;
vec3    _position;
vec4    _rotation;
vec3    _scale;
然后在构造函数中,我初始化变量,如下所示:

_model = mat4::identity();
_position = vec3(0.0f, 0.0f, 0.0f);
_rotation = vec4(0.0f, 1.0f, 0.0f, 0.0f);
_scale = vec3(1.0f, 1.0f, 1.0f);

_u_model = glGetUniformLocation(shader->_program, "model");
最后,我使用以下公式更新模型矩阵:

_model =            translate(_position) *
                    rotate(_rotation.data[0], _rotation.data[1], _rotation.data[2], _rotation.data[3]) *
                    scale(_scale);
编辑2:这是我用于MVP的相机等级:

class Camera : public object
{
private:
    CBbool      _director;
    CBfloat     _fov;
    CBfloat     _near;
    CBfloat     _far;
    CBfloat     _speed;
    Math::vec3  _front;
    Math::vec3  _up;
    Math::mat4  _projection;
    Math::mat4  _view;

    CBuint      _u_projection;
    CBuint      _u_view;

public:
    Camera(Shader* shader, Math::vec3 pos, float fov, float n, float f, bool dir) : _speed(5.0f)
    {
        _model = Math::mat4::identity();
        _projection = Math::mat4::identity();
        _view = Math::mat4::identity();

        _position = pos;
        _fov = fov;
        _near = n;
        _far = f;
        _director = dir;
        _front = vec3(0.0f, 0.0f, -1.0f);
        _up = vec3(0.0f, 1.0f, 0.0f);

        _u_projection = glGetUniformLocation(shader->_program, "projection");
        _u_view = glGetUniformLocation(shader->_program, "view");
        _u_model = glGetUniformLocation(shader->_program, "view_loc");
    }

    ~Camera() {}


    inline CBbool isDirector()          { return _director; }

    inline void forward(double delta)   { _position.data[2] -= _speed * (float)delta; }
    inline void back(double delta)      { _position.data[2] += _speed * (float)delta; }
    inline void left(double delta)      { _position.data[0] -= _speed * (float)delta; }
    inline void right(double delta)     { _position.data[0] += _speed * (float)delta; }
    inline void up(double delta)        { _position.data[1] += _speed * (float)delta; }
    inline void down(double delta)      { _position.data[1] -= _speed * (float)delta; }

    virtual void update(double delta)
    {
        _view = Math::lookat(_position, _position + _front, _up);
        _projection = Math::perspective(_fov, 900.0f / 600.0f, _near, _far);
    }

    virtual void render()
    {
        glUniformMatrix4fv(_u_view, 1, GL_FALSE, _view);
        glUniformMatrix4fv(_u_projection, 1, GL_FALSE, _projection);
        glUniform3f(_u_model, _position.data[0], _position.data[1], _position.data[2]);
    }
};

正如Amadeus提到的,我只需使用
gl_Position=vec4(Position,1.0f)以使其渲染。不知道为什么,但现在是时候知道了!谢谢您的时间。

好的,没有看到完整的程序很难说,但是,您的程序(着色器)构造是否正确?您是如何初始化制服的(投影、视图和模型)?为了缩小可能性,在顶点着色器中,执行:
gl_Position=vec4(位置,1.0f)谢谢你的回答,我已经编辑了上面的问题^。我将测试gl_position=vec4(位置,1.0f);看看这是否是问题所在,谢谢!哦,哇!它起作用了!非常感谢你你帮我节省了很多时间,谢谢!!!因为您没有正确初始化统一矩阵(投影、视图和模型)。换句话说,只要使它们等于identityes好吧,我实际上在一个摄影机类中使用了这三种制服,我将进行第二次编辑并向您展示我所拥有的。似乎只是忽略了为MVP制服设置的值:在渲染EBO之前,SI没有获得模型制服!现在可以了,谢谢你的帮助!