OpenGL：在 python 中加载时模型看起来不正确
我有一个搅拌机模型，下面是我的模型在将其加载到 python 中时如何呈现的图像。看起来法线都乱了。我为每个顶点使用正确的法线。我正在以正确的顺序导出它们。我在搅拌机控制台中测试了实际导出文件是否具有正确的数据。
我知道我必须在 python 中旋转模型，因为 z 轴不同，所以我不确定法线 z 是否指向错误的方向。
我正在使用 pyglet。以前有人遇到过这个问题吗？ 我能做些什么来尝试修复它有什么想法吗？
我不确定这是 OpenGL 还是 python 问题。
opengl 设置代码：
glMatrixMode(GL_PROJECTION)
zNear = 0.01
zFar = 1000.0
fieldOfView = 45.0
size = zNear * math.tan(math.radians(fieldOfView) / 2.0)
glFrustum(-size, size, -size / (w / h), size /
(w / h), zNear, zFar);
glViewport(0, 0, w, h);
# Set-up projection matrix
# TODO
glMatrixMode(GL_MODELVIEW)
glShadeModel(GL_SMOOTH)
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)
light0Ambient = (GLfloat * 4)(*[])
light0Ambient[0] = 0.2
light0Ambient[1] = 0.2
light0Ambient[2] = 0.2
light0Ambient[3] = 1.0
glLightfv(GL_LIGHT0, GL_AMBIENT, light0Ambient);
lightpos = (GLfloat * 3)(*[])
lightpos[0] = 5.0
lightpos[1] = 5.0
lightpos[2] = 5.0
glLightfv(GL_LIGHT0, GL_POSITION, lightpos)
tempLV = self.kjgCreateVectorWithStartandEndPoints((5.0,5.0,5.0), (0.0,0.0,-3.0))
lightVector = (GLfloat * 3)(*[])
lightVector[0] = tempLV[0]
lightVector[1] = tempLV[1]
lightVector[2] = tempLV[2]
glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION,lightVector);
glLoadIdentity( )
glTranslatef(0.0, 2.0, -18.0)
#glScalef(0.4, 0.4, 0.4)
glRotatef(-90, 1.0, 0.0, 0.0)
绘制代码：
for face in self.faces:
#print group
if len(face) == 3:
glBegin(GL_TRIANGLES)
elif len(face) == 4:
glBegin(GL_QUADS)
else:
glBegin(GL_POLYGON)
for i in face:
if i in (104,16,18,102):
glVertex3f(*self.vertices[i])
color = self.calculateVertexIntensity((.5,.5,.5),self.normals[i],self.vertices[i])
glColor3f(*color)
glNormal3f(*self.normals[i])
glEnd()
I have a blender model and below is a image of how my model renders when I load it into python. It looks like the normals are all messed up. I am using the correct normal for each vertex. I'm exporting them in the correct order. I test this in the blender console that the actual export file had the right data.
I know that I had to rotate the model in python because z axis is different, so I'm not sure if the normals z is pointing in the wrong direction.
I'm using pyglet. Has anyone ever had this problem before?
Any ideas of what I can do to try to fix it?
Im not sure if this a OpenGL or python problem.
opengl setup code:
glMatrixMode(GL_PROJECTION)
zNear = 0.01
zFar = 1000.0
fieldOfView = 45.0
size = zNear * math.tan(math.radians(fieldOfView) / 2.0)
glFrustum(-size, size, -size / (w / h), size /
(w / h), zNear, zFar);
glViewport(0, 0, w, h);
# Set-up projection matrix
# TODO
glMatrixMode(GL_MODELVIEW)
glShadeModel(GL_SMOOTH)
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)
light0Ambient = (GLfloat * 4)(*[])
light0Ambient[0] = 0.2
light0Ambient[1] = 0.2
light0Ambient[2] = 0.2
light0Ambient[3] = 1.0
glLightfv(GL_LIGHT0, GL_AMBIENT, light0Ambient);
lightpos = (GLfloat * 3)(*[])
lightpos[0] = 5.0
lightpos[1] = 5.0
lightpos[2] = 5.0
glLightfv(GL_LIGHT0, GL_POSITION, lightpos)
tempLV = self.kjgCreateVectorWithStartandEndPoints((5.0,5.0,5.0), (0.0,0.0,-3.0))
lightVector = (GLfloat * 3)(*[])
lightVector[0] = tempLV[0]
lightVector[1] = tempLV[1]
lightVector[2] = tempLV[2]
glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION,lightVector);
glLoadIdentity( )
glTranslatef(0.0, 2.0, -18.0)
#glScalef(0.4, 0.4, 0.4)
glRotatef(-90, 1.0, 0.0, 0.0)
Draw Code:
for face in self.faces:
#print group
if len(face) == 3:
glBegin(GL_TRIANGLES)
elif len(face) == 4:
glBegin(GL_QUADS)
else:
glBegin(GL_POLYGON)
for i in face:
if i in (104,16,18,102):
glVertex3f(*self.vertices[i])
color = self.calculateVertexIntensity((.5,.5,.5),self.normals[i],self.vertices[i])
glColor3f(*color)
glNormal3f(*self.normals[i])
glEnd()
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现在，您正在指定顶点之后的法线，而不是之前，因此基本上您是在为顶点 X+1 指定顶点 X 的法线。这是当前代码中最重要的缺陷。
另外，
calculateVertexIntensity是什么？首先，您的代码中启用了光照，因此glColor无论如何都会被忽略，但看起来您仍然试图在这里做一些不必要的事情 - OpenGL 固定函数渲染已经会计算顶点强度基于glLight*设置和glMaterial*设置。另外，您可能想要标准化您的
lightVector，我不确定 OpenGL 是否会为您标准化它。（还要确保检查最新的 OpenGL 功能；您现在正在使用已弃用的函数，因此您很快就会遇到性能障碍。首先要查找的是
顶点数组或VBO，下一个是着色器。）Right now you are specifying the normal after the vertex instead of before, so basically you're specifying the normal of vertex X for the vertex X+1. This is the most important flaw in the current code.
Also, what's that
calculateVertexIntensity? First of all, lighting is enabled in your code soglColoris going to be ignored anyway, but still it looks like you tried to do something unnecessary here - the OpenGL fixed function rendering already will calculate the vertex intensity basing on theglLight*settings andglMaterial*settings.Also, you might want to normalize your
lightVector, I'm not sure whether OpenGL's going to normalize it for you.(Also make sure to check on the recent OpenGL features; you're using deprecated functions right now and because of that you'll soon hit a performance barrier. First thing too look for is
vertex arraysorVBO, the next isshaders.)这看起来像是你的法线有问题。
self.normals 中的数据可能是错误的：您应该重新计算法线，确保始终使用面周围逆时针方向的一系列顶点来计算每个法线。
（另外，您应该在绘制每个顶点/面之前调用 glNormal）
（另外，我不知道当您计算每个顶点的颜色时发生了什么：但请检查这是否会导致问题）
This looks like a problem with your normals.
The data in
self.normalsis probably wrong: you should recalculate normals making sure that you always use a sequence of vertices in the anticlockwise direction around the face to calculate each normal.(also, you should be calling glNormal before drawing each vertex / face)
(also also, I don't know what's going on when you calculate the colour for each vertex: but check that that isn't causing problems)