C++ OpenGL Terrain 3D calcul法线顶点->；模糊

为了使地形的曲面外观更平滑，解决方案是将单个法线与三角形相关联，而不是将法线与三角形的三个顶点中的每个顶点相关联

所以，当我尝试实现它时，我发现了一些问题，比如模糊

这是我试图做的事情的一个计划：

我正在使用以下代码：

    for (int i=0;i<nb_pt_z;i++)
{
    for (int j=0;j<nb_pt_x;j++)
    {
        Vector N(0.0, 0.0, 0.0);

        if (i != 0)
        {
            if (j != 0)
            {
                Vector v1(points_terrain[((i-1)*nb_pt_x)+j].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i-1)*nb_pt_x)+j].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i-1)*nb_pt_x)+j].z-points_terrain[(i*nb_pt_x)+j].z);

                Vector v2(points_terrain[(i*nb_pt_x)+(j-1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[(i*nb_pt_x)+(j-1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[(i*nb_pt_x)+(j-1)].z-points_terrain[(i*nb_pt_x)+j].z);

                N += v1^v2;
            }

            if (j != nb_pt_z-1)
            {
                Vector v1(points_terrain[((i-1)*nb_pt_x)+(j+1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i-1)*nb_pt_x)+(j+1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i-1)*nb_pt_x)+(j+1)].z-points_terrain[(i*nb_pt_x)+j].z);

                Vector v2(points_terrain[((i-1)*nb_pt_x)+j].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i-1)*nb_pt_x)+j].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i-1)*nb_pt_x)+j].z-points_terrain[(i*nb_pt_x)+j].z);

                N += v1^v2;

                Vector v3(points_terrain[(i*nb_pt_x)+(j+1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[(i*nb_pt_x)+(j+1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[(i*nb_pt_x)+(j+1)].z-points_terrain[(i*nb_pt_x)+j].z);

                Vector v4(points_terrain[((i-1)*nb_pt_x)+(j+1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i-1)*nb_pt_x)+(j+1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i-1)*nb_pt_x)+(j+1)].z-points_terrain[(i*nb_pt_x)+j].z);

                N+= v3^v4;
            }
        }

        if (i != nb_pt_x-1)
        {
            if (j != 0)
            {
                Vector v1(points_terrain[(i*nb_pt_x)+(j-1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[(i*nb_pt_x)+(j-1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[(i*nb_pt_x)+(j-1)].z-points_terrain[(i*nb_pt_x)+j].z);

                Vector v2(points_terrain[((i+1)*nb_pt_x)+(j-1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i+1)*nb_pt_x)+(j-1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i+1)*nb_pt_x)+(j-1)].z-points_terrain[(i*nb_pt_x)+j].z);

                N+= v1^v2;

                Vector v3(points_terrain[((i+1)*nb_pt_x)+(j-1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i+1)*nb_pt_x)+(j-1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i+1)*nb_pt_x)+(j-1)].z-points_terrain[(i*nb_pt_x)+j].z);

                Vector v4(points_terrain[((i+1)*nb_pt_x)+j].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i+1)*nb_pt_x)+j].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i+1)*nb_pt_x)+j].z-points_terrain[(i*nb_pt_x)+j].z);

                N+= v3^v4;
            }

            if (j != nb_pt_z-1)
            {
                Vector v3(points_terrain[((i+1)*nb_pt_x)+j].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[((i+1)*nb_pt_x)+j].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[((i+1)*nb_pt_x)+j].z-points_terrain[(i*nb_pt_x)+j].z);

                Vector v4(points_terrain[(i*nb_pt_x)+(j+1)].x-points_terrain[(i*nb_pt_x)+j].x,
                          points_terrain[(i*nb_pt_x)+(j+1)].hauteur-points_terrain[(i*nb_pt_x)+j].hauteur,
                          points_terrain[(i*nb_pt_x)+(j+1)].z-points_terrain[(i*nb_pt_x)+j].z);

                N+= v3^v4;
            }
        }
        N.normalize();
        points_terrain[(i*nb_pt_x)+j].nx = N.x;
        points_terrain[(i*nb_pt_x)+j].ny = N.y;
        points_terrain[(i*nb_pt_x)+j].nz = N.z;

    }
}

我正在使用顶点数组来绘制这些点

num = 0;
for( z=0; z<nb_pt_z-1; z++ )
{
    for( x=0; x<nb_pt_x-1; x++ )
    {
        int ind=z*nb_pt_x+x;
        points_indice[num++] =ind;
        points_indice[num++] = ind+nb_pt_x;
        points_indice[num++] = ind+nb_pt_x+1;
        points_indice[num++] = ind;
        points_indice[num++] = ind+nb_pt_x+1;
        points_indice[num++] = ind+1;
    }
}

---

所以，有人知道问题出在哪里吗？

实际上，这看起来像是您交换了一些坐标。检查循环的

顺序是否正确。你面临的问题不是模糊，而是法线的不连续性。是的，我已经检查了，它似乎是正确的。我试图在2-3个晚上纠正这个问题。你的循环表明顶点是x行x行对齐的（内循环超过x），但索引表明不是这样（左邻右舍是
num-nb\u pt\u x
而不是
num-1
）。这似乎不正确。我更新了我的第一篇博文。由于您的回复编辑了我的代码后，它仍然存在。可能是问题出在points\u Indicate选项卡上？（请参阅第一篇博文）您的范围检查错误（
if（j！=nb\u pt\u z-1）
）.
j
属于x轴，
i
属于z轴。但这应该不是问题。您可以尝试从方案中删除三角形。因此，仅从三角形1开始，查看法线是否平滑。
num = 0;
for( z=0; z<nb_pt_z-1; z++ )
{
    for( x=0; x<nb_pt_x-1; x++ )
    {
        int ind=z*nb_pt_x+x;
        points_indice[num++] =ind;
        points_indice[num++] = ind+nb_pt_x;
        points_indice[num++] = ind+nb_pt_x+1;
        points_indice[num++] = ind;
        points_indice[num++] = ind+nb_pt_x+1;
        points_indice[num++] = ind+1;
    }
}

 glInterleavedArrays( GL_T2F_N3F_V3F, 0, points_terrain );
glDrawElements( GL_TRIANGLES, nbIndice,
               GL_UNSIGNED_INT, points_indice );