聚光灯问题OpenGL

Question

我在OpenGL库中遇到聚光灯问题。如果GL_SPOT_CUTOFF小于125，则场景为黑色，灯光不可见。我认为这个问题和光源的方向有关，但我已经尝试了很多聚光灯的位置和方向的选择。这是我的代码：

const GLfloat light_ambient[] = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
glPushMatrix();
glLoadIdentity();
GLfloat spot_direction[] = { 0.0, -1.0, 0.0 ,0.0};
GLfloat spot_position[] = { 1.0,1.0,0.0,1.0 };
glLightfv(GL_LIGHT1, GL_POSITION, spot_position);
glLightfv(GL_LIGHT1, GL_AMBIENT, light_ambient);
glLightfv(GL_LIGHT1, GL_DIFFUSE, light_diffuse);
glLightfv(GL_LIGHT1, GL_SPECULAR, light_specular);
glLightf(GL_LIGHT1, GL_SPOT_CUTOFF, 60);
glLightfv(GL_LIGHT1, GL_SPOT_DIRECTION, spot_direction);
glLightf(GL_LIGHT1, GL_SPOT_EXPONENT, 100);
glPopMatrix();
glEnable(GL_LIGHT1);

Answer 1

已解决。问题是GL_SPOT_EXPONENT因子过高（光线过于聚焦）和光线流的方向。