How to change default color of GlBarGraphItem in PYQTgraph

Question

My goal is to create stacked 3d bar plot, for that, I am trying to change color of GlBarGraphItem from PYQTgraph library.

Here is my code:

from pyqtgraph.Qt import QtCore, QtGui
import pyqtgraph.opengl as gl
import numpy as np 

app = QtGui.QApplication([])
w = gl.GLViewWidget()
w.opts['distance'] = 100
w.showMaximized()
w.setWindowTitle('pyqtgraph example: GLViewWidget')

ax = gl.GLAxisItem()
ax.setSize(20,20,20)
w.addItem(ax)

pos = np.mgrid[0:1,0:1,0:1].reshape(3,1,1).transpose(1,2,0)

size = np.empty((1,1,3)) 
size[...,0:2] = 1
size[...,2] = 5

bg = gl.GLBarGraphItem(pos, size)
##bg.setColor(1., 1., 1., 1.)
w.addItem(bg)

if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()

I tried to use .setColor() method with no success, the object (GlBarGraphItem) itself does not have a method for setting color I believe.

Any hint how to progress?

Answer 1

If the code of the GLMeshItem paint() method is revised:

if self.colors is None:
    color = self.opts['color']
    if isinstance(color, QtGui.QColor):
        glColor4f(*fn.glColor(color))
    else:
        glColor4f(*color)

so the setColor() function expects a QColor or a tuple of 4 elements so you can use the following methods:

bg.setColor((0., 1., 0., 1))

color = QtGui.QColor("pink")
bg.setColor(color)

color = QtGui.QColor(120, 14, 12)
bg.setColor(color)