概述：我正在尝试从绘制调用到示例化。我想保持对各个顶点颜色的控制。
工作材料：C++、OpenGL、Macos。我正在和三个四人组一起工作。三个四边形 * 每个四边形两个唯一三角形= 18个单独顶点。
预期结果：三个四边形，其颜色由总共18个唯一的用户确定的顶点颜色插值。每个四象限有六种独特的颜色。
我能做的：我目前能够示例化顶点位置的变换矩阵，并生成3个有意定位的四边形。
我还不能做的事：我一直无法使我的设置检索每一个传入的顶点正好一种颜色。这是我所知道的最小情况。最小值是它有模型顶点位置，变换位置，和（希望）* 唯一的颜色。
我尝试过的：阅读大量的Kronos函数签名，探索glBufferData（），glVertexAttribPointer（）和glDrawArraysInstanced（）函数中有限可变值的所有参数空间，直到无用。
main.cpp:

#define VTXPOSLOC 0 // Vertex Position Location
#define INSCOLLOC 1 // Instance Color Location
#define INSMATLOC 2 // Instance Matrix Location
...
float vtxdat[18]   = {  0.0f, 0.0f, 0.0f,   1.0f, 0.0f, 0.0f,   1.0f, 1.0f, 0.0f,
                        0.0f, 0.0f, 0.0f,   1.0f, 1.0f, 0.0f,   0.0f, 1.0f, 0.0f };
    std::vector <glm::mat4> iMV; // instanceMatricesVec
    std::vector <glm::vec3> iCV; // instanceColorsVec
    unsigned int instanceCount = 3;
    for (unsigned int i=0; i<instanceCount; i++){
        for (int j=0; j<6; j++) // 6 == number of vertices req to make TWO unique triangles in vtxdat
        {
            float xC = j/2.0f; 
            float yC = i/2.0f;
            glm::vec3 colorvec3 = glm::vec3(xC,yC,0.0f);
            iCV.push_back(colorvec3);
        }

        glm::mat4 transmat4 = glm::translate ( glm::mat4(1.0f), glm::vec3 ( i,0,0 ) );
        iMV.push_back(transmat4);
    }
    glUseProgram      ( shadprogID ); // Does NOT need to be here. ONLY in while loop.
    glGenVertexArrays ( 1, &VAO );
    glBindVertexArray ( VAO );
    glGenBuffers      ( 1, &VBO );
    glBindBuffer      ( GL_ARRAY_BUFFER,VBO );
    glBufferData      ( GL_ARRAY_BUFFER,sizeof(vtxdat),vtxdat,GL_STATIC_DRAW );
    glVertexAttribPointer     ( VTXPOSLOC,3,GL_FLOAT,GL_FALSE,3*sizeof(float),(void*)(0*sizeof(float)));
    glEnableVertexAttribArray ( VTXPOSLOC );
    
    glGenBuffers      ( 1, &colorVBO );
    glBindBuffer      ( GL_ARRAY_BUFFER,colorVBO );
    glBufferData      ( GL_ARRAY_BUFFER,iCV.size() * sizeof(glm::vec3),iCV.data(),GL_STATIC_DRAW );
    glVertexAttribPointer     ( INSCOLLOC,3,GL_FLOAT,GL_FALSE,6*sizeof(float),(void*)(0));
    glEnableVertexAttribArray ( INSCOLLOC );
    
    glGenBuffers      ( 1, &instanceVBO );
    glBindBuffer      ( GL_ARRAY_BUFFER,instanceVBO );
    glBufferData      ( GL_ARRAY_BUFFER,iMV.size() * sizeof(glm::mat4),iMV.data(),GL_STATIC_DRAW );
    
    for (int i = 0; i < 4; i++) {
        glVertexAttribPointer     ( INSMATLOC+i,4,GL_FLOAT,GL_FALSE,sizeof(glm::mat4),(void*)(i*sizeof(glm::vec4)));
        glEnableVertexAttribArray ( INSMATLOC+i );
        glVertexAttribDivisor     ( INSMATLOC+i, 1 );
    }

    while ( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS && glfwWindowShouldClose(window) == 0 ) {
...        
        glm::mat4 projmat4 = glm::perspective(glm::radians(fov), (float)WINDOWWIDTH / (float)WINDOWHEIGHT, 0.1f, 100.0f);
        glm::mat4 viewmat4 = glm::lookAt(camPs, camPs + camFr, camUp);
        
        glUniformMatrix4fv(projmat4ID, 1, GL_FALSE, &projmat4[0][0]); // to vs
        glUniformMatrix4fv(viewmat4ID, 1, GL_FALSE, &viewmat4[0][0]); // to vs
              
        glDrawArraysInstanced(GL_TRIANGLES, 0, 6, instanceCount);
...
    };

字符串
顶点着色器：

#version 330 core
layout(location = 0) in vec3 vtxPos;
layout(location = 1) in vec3 iCV;
layout(location = 2) in mat4 iMV;
out vec3 fragmentColor;
uniform mat4 projmat4;
uniform mat4 viewmat4;
void main(){
    vec4 transformedPos = iMV * vec4(vtxPos,1.0f);
    gl_Position = projmat4 * viewmat4 * transformedPos;
    fragmentColor = iCV;
}

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