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Problem setting background color in pyqtgraph

I have a problem while using the pyqtgraph module in python. When I put white background color in glscatterplot, the scatter points just disappear. It's like the background color has been added to the scatterplot color, so everything is white. Here is the piece of code I am using:

w = gl.GLViewWidget()
w.setBackgroundColor('w')
w.show()
sp3 = gl.GLScatterPlotItem(pos=np.transpose(pos3), color=rgba_img, size=1, pxMode=False)
w.addItem(sp3)

If I replace ('w') with ('k') in the setBackgroundColor method, the scatter color is fine and the background is black. Has anyone else got this problem?

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3 answers


I think the reason is because you didn't set the foreground color. try:



import pyqtgraph as pg

pg.setConfigOption('background', 'w')
pg.setConfigOption('foreground', 'k')
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In pyqtgraph, you create a QApplication in front of the QPaintDevice:

import pyqtgraph as pg

def mkQApp():
    global QAPP
    QtGui.QApplication.setGraphicsSystem('raster')
    # work around a variety of bugs in the native graphics system
    inst = QtGui.QApplication.instance()
    if inst is None:
        QAPP = QtGui.QApplication([])
    else:
        QAPP = inst
    return QAPP


app = pg.mkQApp()
view  = pg.GraphicsView()#useOpenGL = True)
color='w'
view.setBackground(color)
view.show()


then you can use: plot = pg.PlotItem()

etc.

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I had the same problem and found a solution here: https://github.com/pyqtgraph/pyqtgraph/issues/193 . I think this is the same question, so you probably already know the solution, but I'm posting it here because it's oversimplified.

The problem is that there is an option called glOptions for GLScatterPlotItem. The default is " append " (see Pyqtgraph.opengl.GLGraphicsItem.GLOptions ). You can change it to "semi-transparent", like this:

sp3.setGLOptions('translucent')

This way you won't have any problems with changing the background color to white or scattering the color to black (I had both problems).

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