Linux OpenGL代码失败，在Mac和Windows上运行

Question

我有一个相当复杂的基于Python的OpenGL代码，它在Windows和Mac上运行良好，但在Linux上使用奇怪的带状球体时却失败了。从两个角度看：

下面是相同代码在Mac上绘制的内容：

问题不仅在于球体，而且这是最容易表现出来的。这个问题对任何比我更有OpenGL经验的人有什么建议吗？你知道吗

谢谢你的任何提示或建议。你知道吗

下面是一些显示此问题的示例代码

'''Draws a sphere and axis triplet with openGL; rotates with mouse drag.
This works fine on Windows and Mac, but sphere displays strangely on Linux
'''
import sys
import math
import numpy as np
import numpy.linalg as nl
import wx
import wx.glcanvas
import OpenGL.GL as GL
import OpenGL.GLU as GLU
drawingData = {
    'oldxy' : [0, 0],
    'Quaternion' : np.array([ 0.11783419,  0.87355958,  0.09141639,  0.4633053 ]),
    'linecolors': [(np.array([[0, 0, 0], [1, 0, 0]]), [255,   0,   0]),
                   (np.array([[0, 0, 0], [0, 1, 0]]), [  0, 255,   0]),
                   (np.array([[0, 0, 0], [0, 0, 1]]), [  0,   0, 255])],
}

def Q2Mat(Q):
    ''' make rotation matrix from quaternion
    '''
    QN = Q/np.sqrt(np.sum(np.array(Q)**2))
    aa = QN[0]**2
    ab = QN[0]*QN[1]
    ac = QN[0]*QN[2]
    ad = QN[0]*QN[3]
    bb = QN[1]**2
    bc = QN[1]*QN[2]
    bd = QN[1]*QN[3]
    cc = QN[2]**2
    cd = QN[2]*QN[3]
    dd = QN[3]**2
    M = [[aa+bb-cc-dd, 2.*(bc-ad),  2.*(ac+bd)],
        [2*(ad+bc),   aa-bb+cc-dd,  2.*(cd-ab)],
        [2*(bd-ac),    2.*(ab+cd), aa-bb-cc+dd]]
    return np.array(M)

def prodQVQ(Q,V):
    """compute the quaternion vector rotation qvq-1 = v'
    """
    T2 = Q[0]*Q[1]
    T3 = Q[0]*Q[2]
    T4 = Q[0]*Q[3]
    T5 = -Q[1]*Q[1]
    T6 = Q[1]*Q[2]
    T7 = Q[1]*Q[3]
    T8 = -Q[2]*Q[2]
    T9 = Q[2]*Q[3]
    T10 = -Q[3]*Q[3]
    M = np.array([[T8+T10,T6-T4,T3+T7],[T4+T6,T5+T10,T9-T2],[T7-T3,T2+T9,T5+T8]])
    VP = 2.*np.inner(V,M)
    return VP+V

def invQ(Q):
    '''get inverse of quaternion q=r+ai+bj+ck; q* = r-ai-bj-ck
    '''
    return Q*np.array([1,-1,-1,-1])

def AVdeg2Q(A,V):
    ''' convert angle (degrees) & vector to quaternion
        q=r+ai+bj+ck
    '''
    sind = lambda x: math.sin(x*math.pi/180.)
    cosd = lambda x: math.cos(x*math.pi/180.)
    Q = np.zeros(4)
    d = nl.norm(np.array(V))
    if not A:       #== 0.!
        A = 360.
    if d:
        V = V/d
        p = A/2.
        Q[0] = cosd(p)
        Q[1:4] = V*sind(p)
    else:
        Q[3] = 1.
    return Q

def prodQQ(QA,QB):
    ''' Grassman quaternion product, QA,QB quaternions; q=r+ai+bj+ck
    '''
    D = np.zeros(4)
    D[0] = QA[0]*QB[0]-QA[1]*QB[1]-QA[2]*QB[2]-QA[3]*QB[3]
    D[1] = QA[0]*QB[1]+QA[1]*QB[0]+QA[2]*QB[3]-QA[3]*QB[2]
    D[2] = QA[0]*QB[2]-QA[1]*QB[3]+QA[2]*QB[0]+QA[3]*QB[1]
    D[3] = QA[0]*QB[3]+QA[1]*QB[2]-QA[2]*QB[1]+QA[3]*QB[0]
    return D

def RenderUnitVectors(x,y,z):
    'Show the axes'
    GL.glEnable(GL.GL_COLOR_MATERIAL)
    GL.glLineWidth(2)
    GL.glEnable(GL.GL_BLEND)
    GL.glBlendFunc(GL.GL_SRC_ALPHA,GL.GL_ONE_MINUS_SRC_ALPHA)
    GL.glEnable(GL.GL_LINE_SMOOTH)
    GL.glPushMatrix()
    GL.glTranslate(x,y,z)
    GL.glScalef(1,1,1)
    GL.glBegin(GL.GL_LINES)
    for line,color in drawingData['linecolors']:
            GL.glColor3ubv(color)
            GL.glVertex3fv(-line[1]/2.)
            GL.glVertex3fv(line[1]/2.)
    GL.glEnd()
    GL.glPopMatrix()
    GL.glColor4ubv([0,0,0,0])
    GL.glDisable(GL.GL_LINE_SMOOTH)
    GL.glDisable(GL.GL_BLEND)
    GL.glDisable(GL.GL_COLOR_MATERIAL)

def RenderSphere(x,y,z,radius,color):
    'show a sphere'
    GL.glMaterialfv(GL.GL_FRONT_AND_BACK,GL.GL_DIFFUSE,color)
    GL.glPushMatrix()
    GL.glTranslate(x,y,z)        
    GL.glMultMatrixf(np.eye(4).T)
    GLU.gluSphere(GLU.gluNewQuadric(),radius,20,10)
    GL.glPopMatrix()

class myGLCanvas(wx.Panel):
    def __init__(self, parent, id=-1,dpi=None,**kwargs):
        wx.Panel.__init__(self,parent,id=id,**kwargs)
        if 'win' in sys.platform:           # for Windows (& darwin==Mac) -- already double buffered
            attribs = None
        else:                               # Linux
            attribs = [wx.glcanvas.WX_GL_DOUBLEBUFFER,]
        self.canvas = wx.glcanvas.GLCanvas(self,-1,attribList=attribs,**kwargs)
        self.context = wx.glcanvas.GLContext(self.canvas)
        self.canvas.SetCurrent(self.context)
        sizer=wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.canvas,1,wx.EXPAND)
        self.SetSizer(sizer)
        self.canvas.Bind(wx.EVT_MOTION, self.OnMouseMove)
        self.Draw()
        self.Draw()
        return

    def OnMouseMove(self,event):
        if not event.Dragging():
            drawingData['oldxy'] = list(event.GetPosition())
            return
        # Perform a rotation in x-y space
        oldxy = drawingData['oldxy']
        if not len(oldxy): oldxy = list(event.GetPosition())
        dxy = event.GetPosition()-oldxy
        drawingData['oldxy'] = list(event.GetPosition())
        V = np.array([dxy[1],dxy[0],0.])
        A = 0.25*np.sqrt(dxy[0]**2+dxy[1]**2)
        if not A: return
        # next transform vector back to xtal coordinates via inverse quaternion & make new quaternion
        Q = drawingData['Quaternion']
        V = prodQVQ(invQ(Q),np.inner(np.eye(3),V))
        Q = prodQQ(Q,AVdeg2Q(A,V))
        drawingData['Quaternion'] = Q
        self.Draw()

    def Draw(self):
        GL.glClearColor(0.,0.,0.,0.)
        GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)
        GL.glInitNames()
        GL.glPushName(0)

        GL.glMatrixMode(GL.GL_PROJECTION)
        GL.glLoadIdentity()
        GL.glViewport(0,0,*self.canvas.GetSize())
        GLU.gluPerspective(20.,self.canvas.GetSize()[0]*1./self.canvas.GetSize()[1],7.5,12.5)
        GLU.gluLookAt(0,0,10,0,0,0,0,1,0)

        # Set Lighting            
        GL.glEnable(GL.GL_DEPTH_TEST)
        GL.glEnable(GL.GL_LIGHTING)
        GL.glEnable(GL.GL_LIGHT0)
        GL.glLightModeli(GL.GL_LIGHT_MODEL_TWO_SIDE,0)
        GL.glLightfv(GL.GL_LIGHT0,GL.GL_AMBIENT,[1,1,1,1])
        GL.glLightfv(GL.GL_LIGHT0,GL.GL_DIFFUSE,[1,1,1,1])

        GL.glMatrixMode(GL.GL_MODELVIEW)
        GL.glLoadIdentity()
        matRot = Q2Mat(drawingData['Quaternion'])
        matRot = np.concatenate((np.concatenate((matRot,[[0],[0],[0]]),axis=1),[[0,0,0,1],]),axis=0)
        GL.glMultMatrixf(matRot.T)
        GL.glMultMatrixf(np.eye(4).T)
        Tx,Ty,Tz = (0.20045985394544949, 0.44135342324377724, 0.40844172594191536)
        GL.glTranslate(-Tx,-Ty,-Tz)
        RenderUnitVectors(Tx,Ty,Tz)
        RenderSphere(0, 0, 0, 0.804, [1.,  1.,  1.])
        self.canvas.SetCurrent(self.context)
        self.canvas.SwapBuffers()

class GUI(wx.App):
    def OnInit(self):
        frame = wx.Frame(None,-1,'ball rendering',wx.DefaultPosition,wx.Size(400,400))
        frame.Show()
        wx.CallAfter(myGLCanvas,frame,size=wx.Size(400,400)) # wait for frame to be displayed
        self.MainLoop()
        return True

if __name__ == '__main__':
    GUI()

Answer 1

必须根据硬件条件，通过设置^{}来指定深度缓冲区的位数。深度缓冲区的大小应为16、24或32。你知道吗

attribs = [
     wx.glcanvas.WX_GL_RGBA,
     wx.glcanvas.WX_GL_DOUBLEBUFFER,
     wx.glcanvas.WX_GL_DEPTH_SIZE, 16]

另请参见：

• How can I determine the max allowable WX_GL_DEPTH_SIZE for a wx GLCanvas?
• OpenGL depth buffer deosn't seem to work in wx.glcanvas?
• wx.glcanvas.WX_GL_DEPTH_SIZE
• wxGLCanvas