paintGL 不在屏幕上绘制任何东西
paintGL does not draw anything on the screen
我正在尝试基于来自 OpenGL Wiki 的 example 创建 PyQt5/ PyOpenGL 代码。
paintGL() 调用不会在屏幕上呈现任何内容。我读过的具有相似标题的 Whosebug 问题描述了与我面临的问题不同的问题：
注意：由于代表限制，我目前无法 post 超过 2 个链接。我已将所有相关的 Whosebug 链接添加为对此问题的评论。
我也浏览了 Common OpenGL Mistakes 页面，但似乎没有帮助（很可能我没有很好地理解该页面）。
glGetErrors 函数在以下所有阶段报告 GL.GL_NO_ERROR：
- 创建 VAO 绑定时
- 在创建 VBO 绑定时，
- 调用
glBindVertexArray 和 glEnableVertexAttribArray 之后
glGetShaderiv和glGetProgramivreturnGL.GL_TRUE，所以好像没有编译链接错误。
似乎已正确创建 GL 上下文。 self.context().isValid() 检查 returns True.
我正在使用 PyQt5.5，Python 3.4.0 和 PyOpenGL 3.1。此外，GPU Caps Viewer 报告说我的机器上可以使用 Open GL 4.5。
非常感谢任何有助于移动的帮助或指示。
代码如下。
from PyQt5 import QtGui, QtCore
import sys, array
from OpenGL import GL
# Create the Vertex Shader script and the Fragment Shader script here.
DeltaVertexShader = '''
#version 420 core
layout (location = 0) in vec4 vertexPositions;
layout (location = 1) in vec4 vertexColours;
smooth out vec4 fragmentColours;
void main()
{
gl_Position = vertexPositions;
fragmentColours = vertexColours;
}
'''
DeltaFragmentShader = '''
#version 420 core
smooth in vec4 fragmentColours;
out vec4 finalColours;
void main()
{
finalColours = fragmentColours;
}
'''
class PulleysWithWeights3D( QtGui.QOpenGLWindow ):
def __init__(self):
super().__init__()
# These are the 4D coordinates of a triangle that needs to be drawn.
_vertexPos = [ 0.075, 0.075, 0.075, 1.0, \
0.275, 0.275, 0.275, 1.0, \
0.550, 0.550, 0.550, 1.0 ]
# These are the RGBA colours for each vertex.
_vertexCols = [ 0.875, 0.525, 0.075, 0.500, \
0.875, 0.525, 0.075, 0.500, \
0.875, 0.525, 0.075, 0.500 ]
self._deltaPositions = array.array( 'f', _vertexPos )
self._deltaColours = array.array( 'f', _vertexCols )
self._appSurfaceFormat = QtGui.QSurfaceFormat()
self._appSurfaceFormat.setProfile( QtGui.QSurfaceFormat.CoreProfile )
self._appSurfaceFormat.setMajorVersion( 4 )
self._appSurfaceFormat.setMinorVersion( 2 )
self._appSurfaceFormat.setRenderableType( QtGui.QSurfaceFormat.OpenGL )
self._appSurfaceFormat.setSamples( 16 )
self._appSurfaceFormat.setSwapBehavior( QtGui.QSurfaceFormat.DoubleBuffer )
self.setSurfaceType( QtGui.QSurface.OpenGLSurface )
self.setFormat( self._appSurfaceFormat )
self.setIcon( QtGui.QIcon('OpenGL.png') )
self.setTitle( 'Pulleys3D' )
self.setMinimumSize( QtCore.QSize( 1280, 640 ) )
self.show()
def initializeGL(self):
GL.glClearColor( 0.0, 0.0, 0.00, 1.0 ) # RGBA
GL.glClearDepthf(1.0)
GL.glClearStencil(0)
GL.glClear( GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT | GL.GL_STENCIL_BUFFER_BIT )
# Initialize a VAO.
self._vaoColouredDelta = GL.glGenVertexArrays(1)
GL.glBindVertexArray( self._vaoColouredDelta )
# Initialize the VBOs.
self._vboPositions = GL.glGenBuffers(1) # Create the position buffer.
self._vboShades = GL.glGenBuffers(1) # Create the colours buffer.
# Bind the positions VBO to the GL_ARRAY_BUFFER target.
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, self._vboPositions )
# Initialize the positions buffer with the positions array data.
GL.glBufferData( GL.GL_ARRAY_BUFFER, self._deltaPositions.buffer_info()[1] * self._deltaPositions.itemsize, \
self._deltaPositions.tobytes(), GL.GL_STATIC_DRAW )
GL.glEnableVertexAttribArray(0) # Enable attribute array 0, i.e., the positions array.
GL.glVertexAttribPointer( 0, 4, GL.GL_FLOAT, GL.GL_FALSE, 0, None )
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, 0 )
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, self._vboShades )
GL.glBufferData( GL.GL_ARRAY_BUFFER, self._deltaColours.buffer_info()[1] * self._deltaColours.itemsize, \
self._deltaColours.tobytes(), GL.GL_STATIC_DRAW )
GL.glEnableVertexAttribArray(1) # Enable attribute array 1, i.e., the colours array.
GL.glVertexAttribPointer( 1, 4, GL.GL_FLOAT, GL.GL_FALSE, 0, None )
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, 0 )
GL.glBindVertexArray(0) # Unbind the VAO.
# Initialize the vertex shader and fragment shader program objects.
_vertexShaderObj = GL.glCreateShader( GL.GL_VERTEX_SHADER )
_fragmentShaderObj = GL.glCreateShader( GL.GL_FRAGMENT_SHADER )
GL.glShaderSource( _vertexShaderObj, DeltaVertexShader )
GL.glShaderSource( _fragmentShaderObj, DeltaFragmentShader )
GL.glCompileShader( _vertexShaderObj )
GL.glCompileShader( _fragmentShaderObj )
if GL.glGetShaderiv( _vertexShaderObj, GL.GL_COMPILE_STATUS ) != GL.GL_TRUE:
# There was a compilation error. Print it.
print( 'Vertex Shader Compilation failed! Details follow.' )
print( 'Compilation errors are: %s ' %( str( GL.glGetShaderInfoLog( _vertexShaderObj ) ) ) )
# Delete this shader.
GL.glDeleteShader( _vertexShaderObj )
return # Don't continue execution.
elif GL.glGetShaderiv( _fragmentShaderObj, GL.GL_COMPILE_STATUS ) != GL.GL_TRUE:
print( 'Fragment Shader Compilation failed! Details follow.' )
print( 'Compilation errors are: %s ' %( str( GL.glGetShaderInfoLog( _fragmentShaderObj ) ) ) )
# Delete this shader.
GL.glDeleteShader( _fragmentShaderObj )
return # Don't continue execution.
self._renderProgram = GL.glCreateProgram()
GL.glAttachShader( self._renderProgram, _vertexShaderObj )
GL.glAttachShader( self._renderProgram, _fragmentShaderObj )
GL.glLinkProgram( self._renderProgram )
if GL.glGetProgramiv( self._renderProgram, GL.GL_LINK_STATUS ) != GL.GL_TRUE:
print( 'Shader linking failed! Details follow.' )
print( 'Linking errors are: %s ' %( str( GL.glGetProgramInfoLog( self._renderProgram ) ) ) )
GL.glDetachShader( self._renderProgram, _vertexShaderObj )
GL.glDetachShader( self._renderProgram, _fragmentShaderObj )
GL.glDeleteShader( _vertexShaderObj )
GL.glDeleteShader( _fragmentShaderObj )
# Delete the program.
GL.glDeleteProgram( self._renderProgram )
return # Don't continue execution.
# Always detach shaders after a successful link.
GL.glDetachShader( self._renderProgram, _vertexShaderObj )
GL.glDetachShader( self._renderProgram, _fragmentShaderObj )
def resizeGL(self, wd, ht ):
# Resize the viewport by calling glViewport with the new height and width.
GL.glViewport( 0, 0, wd, ht )
def paintGL(self):
GL.glClearColor( 0.0, 0.0, 0.00, 1.0 ) # RGBA
GL.glClearDepthf(1.0)
GL.glClearStencil(0)
GL.glClear( GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT | GL.GL_STENCIL_BUFFER_BIT )
# Initialize the shader program to paint.
GL.glUseProgram( self._renderProgram )
GL.glBindVertexArray( self._vaoColouredDelta )
# Draw the array.
GL.glDrawArrays( GL.GL_TRIANGLES, 0, 3 )
# Swap the front and back buffers so the newly drawn content is visible.
self.context().swapBuffers( self )
# Unbind the vertex array and the program.
GL.glBindVertexArray(0)
GL.glUseProgram(0)
if __name__ == '__main__':
_pww3dApp = QtGui.QGuiApplication( sys.argv )
_pww3d = PulleysWithWeights3D()
sys.exit( _pww3dApp.exec_() )
使用的 XYZ 值导致三角形太小而无法被渲染。
放大 X、Y、Z 值将导致显示三角形。例如，
_vertexPos = [ 0.775, 0.775, 0.775, 1.0, \
0.275, 0.275, 0.275, 1.0, \
0.550, 0.550, 0.550, 1.0 ]
我正在尝试基于来自 OpenGL Wiki 的 example 创建 PyQt5/ PyOpenGL 代码。
paintGL() 调用不会在屏幕上呈现任何内容。我读过的具有相似标题的 Whosebug 问题描述了与我面临的问题不同的问题：
注意：由于代表限制，我目前无法 post 超过 2 个链接。我已将所有相关的 Whosebug 链接添加为对此问题的评论。
我也浏览了 Common OpenGL Mistakes 页面，但似乎没有帮助（很可能我没有很好地理解该页面）。
glGetErrors 函数在以下所有阶段报告 GL.GL_NO_ERROR：
- 创建 VAO 绑定时
- 在创建 VBO 绑定时，
- 调用
glBindVertexArray和glEnableVertexAttribArray 之后
glGetShaderiv和glGetProgramivreturnGL.GL_TRUE，所以好像没有编译链接错误。
似乎已正确创建 GL 上下文。 self.context().isValid() 检查 returns True.
我正在使用 PyQt5.5，Python 3.4.0 和 PyOpenGL 3.1。此外，GPU Caps Viewer 报告说我的机器上可以使用 Open GL 4.5。
非常感谢任何有助于移动的帮助或指示。
代码如下。
from PyQt5 import QtGui, QtCore
import sys, array
from OpenGL import GL
# Create the Vertex Shader script and the Fragment Shader script here.
DeltaVertexShader = '''
#version 420 core
layout (location = 0) in vec4 vertexPositions;
layout (location = 1) in vec4 vertexColours;
smooth out vec4 fragmentColours;
void main()
{
gl_Position = vertexPositions;
fragmentColours = vertexColours;
}
'''
DeltaFragmentShader = '''
#version 420 core
smooth in vec4 fragmentColours;
out vec4 finalColours;
void main()
{
finalColours = fragmentColours;
}
'''
class PulleysWithWeights3D( QtGui.QOpenGLWindow ):
def __init__(self):
super().__init__()
# These are the 4D coordinates of a triangle that needs to be drawn.
_vertexPos = [ 0.075, 0.075, 0.075, 1.0, \
0.275, 0.275, 0.275, 1.0, \
0.550, 0.550, 0.550, 1.0 ]
# These are the RGBA colours for each vertex.
_vertexCols = [ 0.875, 0.525, 0.075, 0.500, \
0.875, 0.525, 0.075, 0.500, \
0.875, 0.525, 0.075, 0.500 ]
self._deltaPositions = array.array( 'f', _vertexPos )
self._deltaColours = array.array( 'f', _vertexCols )
self._appSurfaceFormat = QtGui.QSurfaceFormat()
self._appSurfaceFormat.setProfile( QtGui.QSurfaceFormat.CoreProfile )
self._appSurfaceFormat.setMajorVersion( 4 )
self._appSurfaceFormat.setMinorVersion( 2 )
self._appSurfaceFormat.setRenderableType( QtGui.QSurfaceFormat.OpenGL )
self._appSurfaceFormat.setSamples( 16 )
self._appSurfaceFormat.setSwapBehavior( QtGui.QSurfaceFormat.DoubleBuffer )
self.setSurfaceType( QtGui.QSurface.OpenGLSurface )
self.setFormat( self._appSurfaceFormat )
self.setIcon( QtGui.QIcon('OpenGL.png') )
self.setTitle( 'Pulleys3D' )
self.setMinimumSize( QtCore.QSize( 1280, 640 ) )
self.show()
def initializeGL(self):
GL.glClearColor( 0.0, 0.0, 0.00, 1.0 ) # RGBA
GL.glClearDepthf(1.0)
GL.glClearStencil(0)
GL.glClear( GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT | GL.GL_STENCIL_BUFFER_BIT )
# Initialize a VAO.
self._vaoColouredDelta = GL.glGenVertexArrays(1)
GL.glBindVertexArray( self._vaoColouredDelta )
# Initialize the VBOs.
self._vboPositions = GL.glGenBuffers(1) # Create the position buffer.
self._vboShades = GL.glGenBuffers(1) # Create the colours buffer.
# Bind the positions VBO to the GL_ARRAY_BUFFER target.
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, self._vboPositions )
# Initialize the positions buffer with the positions array data.
GL.glBufferData( GL.GL_ARRAY_BUFFER, self._deltaPositions.buffer_info()[1] * self._deltaPositions.itemsize, \
self._deltaPositions.tobytes(), GL.GL_STATIC_DRAW )
GL.glEnableVertexAttribArray(0) # Enable attribute array 0, i.e., the positions array.
GL.glVertexAttribPointer( 0, 4, GL.GL_FLOAT, GL.GL_FALSE, 0, None )
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, 0 )
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, self._vboShades )
GL.glBufferData( GL.GL_ARRAY_BUFFER, self._deltaColours.buffer_info()[1] * self._deltaColours.itemsize, \
self._deltaColours.tobytes(), GL.GL_STATIC_DRAW )
GL.glEnableVertexAttribArray(1) # Enable attribute array 1, i.e., the colours array.
GL.glVertexAttribPointer( 1, 4, GL.GL_FLOAT, GL.GL_FALSE, 0, None )
GL.glBindBuffer( GL.GL_ARRAY_BUFFER, 0 )
GL.glBindVertexArray(0) # Unbind the VAO.
# Initialize the vertex shader and fragment shader program objects.
_vertexShaderObj = GL.glCreateShader( GL.GL_VERTEX_SHADER )
_fragmentShaderObj = GL.glCreateShader( GL.GL_FRAGMENT_SHADER )
GL.glShaderSource( _vertexShaderObj, DeltaVertexShader )
GL.glShaderSource( _fragmentShaderObj, DeltaFragmentShader )
GL.glCompileShader( _vertexShaderObj )
GL.glCompileShader( _fragmentShaderObj )
if GL.glGetShaderiv( _vertexShaderObj, GL.GL_COMPILE_STATUS ) != GL.GL_TRUE:
# There was a compilation error. Print it.
print( 'Vertex Shader Compilation failed! Details follow.' )
print( 'Compilation errors are: %s ' %( str( GL.glGetShaderInfoLog( _vertexShaderObj ) ) ) )
# Delete this shader.
GL.glDeleteShader( _vertexShaderObj )
return # Don't continue execution.
elif GL.glGetShaderiv( _fragmentShaderObj, GL.GL_COMPILE_STATUS ) != GL.GL_TRUE:
print( 'Fragment Shader Compilation failed! Details follow.' )
print( 'Compilation errors are: %s ' %( str( GL.glGetShaderInfoLog( _fragmentShaderObj ) ) ) )
# Delete this shader.
GL.glDeleteShader( _fragmentShaderObj )
return # Don't continue execution.
self._renderProgram = GL.glCreateProgram()
GL.glAttachShader( self._renderProgram, _vertexShaderObj )
GL.glAttachShader( self._renderProgram, _fragmentShaderObj )
GL.glLinkProgram( self._renderProgram )
if GL.glGetProgramiv( self._renderProgram, GL.GL_LINK_STATUS ) != GL.GL_TRUE:
print( 'Shader linking failed! Details follow.' )
print( 'Linking errors are: %s ' %( str( GL.glGetProgramInfoLog( self._renderProgram ) ) ) )
GL.glDetachShader( self._renderProgram, _vertexShaderObj )
GL.glDetachShader( self._renderProgram, _fragmentShaderObj )
GL.glDeleteShader( _vertexShaderObj )
GL.glDeleteShader( _fragmentShaderObj )
# Delete the program.
GL.glDeleteProgram( self._renderProgram )
return # Don't continue execution.
# Always detach shaders after a successful link.
GL.glDetachShader( self._renderProgram, _vertexShaderObj )
GL.glDetachShader( self._renderProgram, _fragmentShaderObj )
def resizeGL(self, wd, ht ):
# Resize the viewport by calling glViewport with the new height and width.
GL.glViewport( 0, 0, wd, ht )
def paintGL(self):
GL.glClearColor( 0.0, 0.0, 0.00, 1.0 ) # RGBA
GL.glClearDepthf(1.0)
GL.glClearStencil(0)
GL.glClear( GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT | GL.GL_STENCIL_BUFFER_BIT )
# Initialize the shader program to paint.
GL.glUseProgram( self._renderProgram )
GL.glBindVertexArray( self._vaoColouredDelta )
# Draw the array.
GL.glDrawArrays( GL.GL_TRIANGLES, 0, 3 )
# Swap the front and back buffers so the newly drawn content is visible.
self.context().swapBuffers( self )
# Unbind the vertex array and the program.
GL.glBindVertexArray(0)
GL.glUseProgram(0)
if __name__ == '__main__':
_pww3dApp = QtGui.QGuiApplication( sys.argv )
_pww3d = PulleysWithWeights3D()
sys.exit( _pww3dApp.exec_() )
使用的 XYZ 值导致三角形太小而无法被渲染。
放大 X、Y、Z 值将导致显示三角形。例如，
_vertexPos = [ 0.775, 0.775, 0.775, 1.0, \
0.275, 0.275, 0.275, 1.0, \
0.550, 0.550, 0.550, 1.0 ]