OpenGL照明随相机改变亮度

Question

所以我刚刚开始玩OpenGL，并决定做一个小的体素渲染。我试着点亮它，但当我绕y轴旋转相机时，会出现奇怪的效果。例如，当我第一次产卵时，光线看起来像这样：

https://i.stack.imgur.com/zQ49y.png

但当我旋转一点时，我会得到：

https://i.stack.imgur.com/PWvVo.png

这是做这件事的代码：

    glRotatef(xrot, 1.0f, 0.0f, 0.0);
    glRotatef(yrot, 0.0f, 1.0f, 0.0);
    glTranslatef(-3.5f-xcam, ycam, -3.5f-zcam);
    glEnable (GL_DEPTH_TEST); //enable the depth testing
    glEnable (GL_LIGHTING); //enable the lighting
    glEnable (GL_LIGHT0);
    GLfloat specular[] = {1.0f-xcam, ycam+1.0, 1.0f-zcam, 1.0};
    glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, grnd);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glBegin(GL_QUADS);
    glTexCoord2i(0, 0);
    glVertex3f(0, 0, 0);
    glTexCoord2i(0, 1);
    glVertex3f(0, 0, 7.0f);
    glTexCoord2i(1, 1);
    glVertex3f(7.0f, 0, 7.0f);
    glTexCoord2i(1, 0);
    glVertex3f(7.0f, 0, 0);
    glEnd();
    glDisable(GL_TEXTURE_2D);
    glLoadIdentity();
    drawVoxel(2.f, 0.f, 2.f, tex);
    drawVoxel(1.f, 0.f, 1.f, tex);
    drawVoxel(2.f, 0.f, 2.f, tex);
    drawVoxel(3.f, 0.f, 3.f, tex);
    drawVoxel(4.f, 0.f, 4.f, tree);
    drawVoxel(4.f, 1.f, 4.f, tree);
    drawVoxel(4.f, 2.f, 4.f, tree);
    drawVoxel(4.f, 3.f, 4.f, tree);
    test.Flip();

有人知道发生了什么事吗？

Answer 1

您还需要使用glNormal3f（）。

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glBegin(GL_QUADS);
glTexCoord2i(0, 0);
glNormal3f(0,1,0);
glVertex3f(0, 0, 0);
glTexCoord2i(0, 1);
glNormal3f(0,1,0);
glVertex3f(0, 0, 7.0f);
glTexCoord2i(1, 1);
glNormal3f(0,1,0);
glVertex3f(7.0f, 0, 7.0f);
glTexCoord2i(1, 0);
glNormal3f(0,1,0);
glVertex3f(7.0f, 0, 0);
glEnd();