OpenGL对象没有光照

Question

我无法让我的模型正常发光。我正在制作一个由 cubes/voxels 组成的物体，所有面都具有相同的光强度。我正在 Python 中编写代码，并将 numpy 用于数组。我的点数组是一个 flat/1D 三角形角点数组。我的法线数组是每个三角形的 flat/1D 法线 3d 向量数组。

以下代码在初始化过程中：

# ===============================================
# First add points to buffer
# ===============================================
points = numpy.array(points,dtype=numpy.float32)
points=points * scale
self.voxelPtBufferLen = len(points) // 3

glEnableClientState(GL_VERTEX_ARRAY)
self.voxelPtBufferIdx = glGenBuffers(1)
dataSizePt = arrays.ArrayDatatype.arrayByteCount(points)

# print ("datasize",dataSize)
glBindBuffer(GL_ARRAY_BUFFER, self.voxelPtBufferIdx)
glBufferData(GL_ARRAY_BUFFER, dataSizePt, points, GL_STATIC_DRAW)

glDisableClientState(GL_VERTEX_ARRAY)

# ===============================================
# Second add normals for each triangle to buffer
# ===============================================
normals = numpy.array(normals, dtype=numpy.float32)
self.voxelNmBufferLen = len(normals)

glEnableClientState(GL_NORMAL_ARRAY)
self.voxelNmBufferIdx = glGenBuffers(1)
dataSizeNm = arrays.ArrayDatatype.arrayByteCount(normals)

glBindBuffer(GL_ARRAY_BUFFER, self.voxelNmBufferIdx)
glBufferData(GL_ARRAY_BUFFER, dataSizeNm, normals, GL_STATIC_DRAW)

glDisableClientState(GL_NORMAL_ARRAY)

然后绘制这个我有以下代码

colorFront = (0.1, 0.3, 0.6)
colorBack = (1, 0.3, 0.3)
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, (0.2, 0.2, 0.2))
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, (0.8, 0.8, 1.0))
glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, 50.0)

glEnable(GL_DEPTH_TEST)
glEnable(GL_NORMALIZE)


glLight(GL_LIGHT1, GL_AMBIENT, (0.3, 0.0, 0.0, 1))
glLight(GL_LIGHT1, GL_DIFFUSE, (0.6, 0.0, 0.0, 1))
glLight(GL_LIGHT1, GL_SPECULAR, (0.9, 0.0, 0.0, 1))
glLight(GL_LIGHT1, GL_POSITION, (10,10,10))
glLight(GL_LIGHT1, GL_SPOT_DIRECTION, (-10,-10,-10))
glEnable(GL_LIGHT1)

glBegin(GL_QUADS)
glColor3f(1.0,1.0,0)
glVertex3f(10, 10, 10)
glVertex3f(12, 12, 12)
glVertex3f(10, 12, 12)
glVertex3f(12, 10, 12)
glEnd()

glPolygonMode(GL_FRONT_AND_BACK, GL_FILL)
glColor3fv(colorFront)

# DRAW VOXELS
glEnableClientState(GL_VERTEX_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, self.voxelPtBufferIdx)
glVertexPointer(3,GL_FLOAT,0,None)

glEnableClientState(GL_NORMAL_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, self.voxelNmBufferIdx)
glNormalPointer(GL_FLOAT, 0, 0)

glDrawArrays(GL_TRIANGLES, 0, self.voxelPtBufferLen)

glDisableClientState(GL_VERTEX_ARRAY)
glDisableClientState(GL_NORMAL_ARRAY)

Answer 1

主要问题是您必须启用照明。见 glEnable:

glEnable(GL_LIGHTING)

启用光照后，网格的颜色由 material 参数决定（glMaterial). See also Basic OpenGL Lighting.

您没有设置环境光 material 参数 (GL_AMBIENT)，漫反射 material 参数 (GL_DIFFUSE) 似乎太弱了。尝试类似的东西：

glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, (0.3, 0.3, 0.3))
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, (1.0, 1.0, 1.0))

OpenGL对象没有光照

OpenGL object no lighting

python

opengl

buffer

light

normals