I tried to use PyBullet but it is very complicated and I cannot understand haw to use it with OpenGL. The Panda3D Bullet wrapper is only one way that I found. And there is a very great manual: https://docs.panda3d.org/1.10/python/programming/physics/bullet/index I hope I will not have unresolved problems with using the Panda3D Bullet wrapper with Qt and OpenGL.

I use:

• the Panda3D Bullet wrapper for Physics
• PyQt5 (and PySide2) for creating a window
• OpenGL 3.3 for rendering

I created a textured cube with Blender and GIMP. I exported the cube to dae (COLLADA) and imported it to my program with built-in Qt XML parser.

PyQt5:

import sys
import numpy as np
from OpenGL import GL as gl
from PyQt5.QtWidgets import QApplication, QOpenGLWidget
from PyQt5.QtGui import QOpenGLShaderProgram, QOpenGLShader, QOpenGLBuffer
from PyQt5.QtGui import QOpenGLTexture, QImage
from PyQt5.QtGui import QMatrix4x4, QVector3D, QQuaternion
from PyQt5.QtXml import QDomDocument, QDomElement
from PyQt5.QtCore import Qt, QFile, QIODevice
from PyQt5.QtCore import QTimer, QElapsedTimer

from panda3d.bullet import BulletWorld
from panda3d.core import TransformState, Vec3, Quat, Point3
from panda3d.bullet import BulletBoxShape
from panda3d.bullet import BulletRigidBodyNode

# Assets:
# Cube Texture: https://dl.dropboxusercontent.com/s/tply9ubx3n3ycvv/cube.png
# Cube Model: https://dl.dropboxusercontent.com/s/0aktc37c3nx9iq3/cube.dae
# Plane Texture: https://dl.dropboxusercontent.com/s/3iibsnvyw0vupby/plane.png
# Plane Model: https://dl.dropboxusercontent.com/s/e0wktg69ec3w8pq/plane.dae

class VertexBuffers:
   vertex_pos_buffer = None
   normal_buffer = None
   tex_coord_buffer = None
   amount_of_vertices = None

class Locations:
   mvp_matrix_location = None
   model_matrix_location = None
   normal_matrix_location = None

class Object3D:
   position = QVector3D(0, 0, 0)
   rotation = QVector3D(0, 0, 0)
   scale = QVector3D(1, 1, 1)
   mvp_matrix = QMatrix4x4()
   model_matrix = QMatrix4x4()
   normal_matrix = QMatrix4x4()

   def __init__(self, vert_buffers, locations, texture, world, mass, pos):
       self.vert_pos_buffer = vert_buffers.vert_pos_buffer
       self.normal_buffer = vert_buffers.normal_buffer
       self.tex_coord_buffer = vert_buffers.tex_coord_buffer
       self.amount_of_vertices = vert_buffers.amount_of_vertices
       
       self.mvp_matrix_location = locations.mvp_matrix_location
       self.model_matrix_location = locations.model_matrix_location
       self.normal_matrix_location = locations.normal_matrix_location
       
       self.texture = texture

       self.shape = BulletBoxShape(Vec3(0.5, 0.5, 0.5))
       self.node = BulletRigidBodyNode('Box')

       self.position = pos
       self.mass = mass
       self.node.setMass(self.mass)

       p = Point3(self.position.x(), self.position.y(), self.position.z())
       q = Quat.identQuat()
       s = Vec3(1, 1, 1)

       self.transform = TransformState.make_pos_quat_scale(p, q, s)
       self.node.setTransform(self.transform)

       self.node.addShape(self.shape)
       self.world = world
       self.world.attachRigidBody(self.node)

   def draw(self, program, proj_view_matrix):
       program.bind()

       self.vert_pos_buffer.bind()
       program.setAttributeBuffer(0, gl.GL_FLOAT, 0, 3)
       program.enableAttributeArray(0)

       self.normal_buffer.bind()
       program.setAttributeBuffer(1, gl.GL_FLOAT, 0, 3)
       program.enableAttributeArray(1)

       self.tex_coord_buffer.bind()
       program.setAttributeBuffer(2, gl.GL_FLOAT, 0, 2)
       program.enableAttributeArray(2)

       self.position.setX(self.node.getTransform().pos.x)
       self.position.setY(self.node.getTransform().pos.y)
       self.position.setZ(self.node.getTransform().pos.z)
       hpr = self.node.getTransform().getHpr()
       pandaQuat = Quat()
       pandaQuat.setHpr(hpr)
       quat = QQuaternion(pandaQuat.getX(), pandaQuat.getY(), pandaQuat.getZ(), pandaQuat.getW())
       
       self.model_matrix.setToIdentity()
       self.model_matrix.translate(self.position)
       self.model_matrix.rotate(quat)
       self.model_matrix.scale(self.scale)
       self.mvp_matrix = proj_view_matrix * self.model_matrix
       
       self.normal_matrix = self.model_matrix.inverted()
       self.normal_matrix = self.normal_matrix[0].transposed()
       
       program.bind()
       program.setUniformValue(self.mvp_matrix_location, self.mvp_matrix)
       program.setUniformValue(self.model_matrix_location, self.model_matrix)
       program.setUniformValue(self.normal_matrix_location, self.normal_matrix)
       
       self.texture.bind()

       gl.glDrawArrays(gl.GL_TRIANGLES, 0, self.amount_of_vertices)

class Window(QOpenGLWidget):

   def __init__(self):
       super().__init__()
       self.setWindowTitle("Bullet Physics")
       self.resize(268, 268)

   def initializeGL(self):
       gl.glClearColor(0.2, 0.2, 0.2, 1)
       gl.glEnable(gl.GL_DEPTH_TEST)
       vertShaderSrc = """
           #version 330 core

           in vec4 aPosition;
           in vec4 aNormal;
           in vec2 aTexCoord;

           uniform mat4 uMvpMatrix;
           uniform mat4 uModelMatrix;
           uniform mat4 uNormalMatrix;

           out vec3 vPosition;
           out vec3 vNormal;
           out vec2 vTexCoord;

           void main()
           {
               gl_Position = uMvpMatrix * aPosition;
               vPosition = vec3(uModelMatrix * aPosition);
               vNormal = normalize(vec3(uNormalMatrix * aNormal));
               vTexCoord = aTexCoord;
           }
       """
       fragShaderSrc = """
           #version 330 core

           const vec3 lightColor = vec3(0.8, 0.8, 0.8);
           const vec3 lightPosition = vec3(5.0, 7.0, 2.0);
           const vec3 ambientLight = vec3(0.3, 0.3, 0.3);

           uniform sampler2D uSampler;

           in vec3 vPosition;
           in vec3 vNormal;
           in vec2 vTexCoord;

           void main()
           {
               vec4 color = texture2D(uSampler, vTexCoord);
               vec3 normal = normalize(vNormal);
               vec3 lightDirection = normalize(lightPosition - vPosition);
               float nDotL = max(dot(lightDirection, normal), 0.0);
               vec3 diffuse = lightColor * color.rgb * nDotL;
               vec3 ambient = ambientLight * color.rgb;
               gl_FragColor = vec4(diffuse + ambient, color.a);
           }
       """
       self.program = QOpenGLShaderProgram()
       self.program.addShaderFromSourceCode(QOpenGLShader.Vertex, vertShaderSrc)
       self.program.addShaderFromSourceCode(QOpenGLShader.Fragment, fragShaderSrc)
       self.program.link()
       self.program.bind()
       self.program.bindAttributeLocation("aPosition", 0)
       self.program.bindAttributeLocation("aNormal", 1)
       self.program.bindAttributeLocation("aTexCoord", 2)
       locations = Locations()
       self.program.bind()
       locations.mvp_matrix_location = self.program.uniformLocation("uMvpMatrix")
       locations.model_matrix_location = self.program.uniformLocation("uModelMatrix")
       locations.normal_matrix_location = self.program.uniformLocation("uNormalMatrix")
       self.vert_buffers = self.initVertexBuffers("assets/cube.dae")
       self.proj_view_matrix = QMatrix4x4()
       self.proj_matrix = QMatrix4x4()
       self.view_matrix = QMatrix4x4()
       self.view_matrix.lookAt(
           QVector3D(2, 3, 5),
           QVector3D(0, 0, 0),
           QVector3D(0, 1, 0))
       
       self.texture = QOpenGLTexture(QOpenGLTexture.Target2D)
       self.texture.create()
       self.texture.setData(QImage("assets/cube.png"))
       self.texture.setMinMagFilters(QOpenGLTexture.Linear, QOpenGLTexture.Linear)
       self.texture.setWrapMode(QOpenGLTexture.ClampToEdge)

       self.world = BulletWorld()
       self.world.setGravity(Vec3(0, -9.81, 0))

       self.obj = Object3D(self.vert_buffers, locations, self.texture, self.world, mass=0, pos=QVector3D(0, -3, 0))
       self.obj2 = Object3D(self.vert_buffers, locations, self.texture, self.world, mass=1, pos=QVector3D(0.8, 3, 0))
       
       #self.move_dir = 1 # move direction: 1 - up, -1 - down
       #self.move_speed = 0.002
       
       self.timer = QTimer()
       self.timer.timeout.connect(self.animationLoop)
       self.elapsed_timer = QElapsedTimer()
       self.elapsed_timer.start()
       self.delta_time = 0
       self.timer.start(1000/60)
       
   def animationLoop(self):
       self.delta_time = self.elapsed_timer.elapsed()
       self.elapsed_timer.restart()
       self.world.doPhysics(self.delta_time / 1000)
       self.update()
       
   def paintGL(self):
       gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
       self.proj_view_matrix = self.proj_matrix * self.view_matrix
       self.obj.draw(self.program, self.proj_view_matrix)
       self.obj2.draw(self.program, self.proj_view_matrix)

   def resizeGL(self, w, h):
       gl.glViewport(0, 0, w, h)
       self.proj_matrix.setToIdentity()
       self.proj_matrix.perspective(50, float(w) / float(h), 0.1, 100)
       
   def initVertexBuffers(self, path):
       xml_doc = QDomDocument()
       file = QFile(path)
       if not file.open(QIODevice.ReadOnly):
           print("Failed to open the file: " + path)
       xml_doc.setContent(file)
       file.close()
       
       vert_pos_array = []
       normal_array = []
       tex_coord_array = []
       index_array = []
       
       root = xml_doc.documentElement()
       dae_elem = root.firstChildElement()
       while not dae_elem.isNull():
           if dae_elem.tagName() == "library_geometries":
               geom_elem = dae_elem.firstChildElement()
               if geom_elem.tagName() == "geometry":
                   mesh_elem = geom_elem.firstChildElement()
                   if mesh_elem.tagName() == "mesh":
                       mesh_child_elem = mesh_elem.firstChildElement()
                       while not mesh_child_elem.isNull():
                           float_array_elem = mesh_child_elem.firstChildElement()
                           str_array = float_array_elem.firstChild().toText().data().split(" ")
                           if mesh_child_elem.attribute("id").endswith("-mesh-positions"):
                               vert_pos_array = list(map(float, str_array))
                           if mesh_child_elem.attribute("id").endswith("-mesh-normals"):
                               normal_array = list(map(float, str_array))
                           if mesh_child_elem.attribute("id").endswith("-mesh-map-0"):
                               tex_coord_array = list(map(float, str_array))
                           if mesh_child_elem.tagName() == "triangles" or mesh_child_elem.tagName() == "polylist":
                               p_child_elem = mesh_child_elem.firstChildElement()
                               while not p_child_elem.isNull():
                                   if p_child_elem.tagName() == "p":
                                       str_indices = p_child_elem.firstChild().toText().data().split(" ")
                                       index_array = list(map(int, str_indices))
                                   p_child_elem = p_child_elem.nextSiblingElement()
                           mesh_child_elem = mesh_child_elem.nextSiblingElement()
           dae_elem = dae_elem.nextSiblingElement()
       # print(vert_pos_array)
       # print(normal_array)
       # print(tex_coord_array)
       # print(index_array)
       
       num_of_attributes = 3
       vert_positions = []
       normals = []
       tex_coords = []
       for i in range(0, len(index_array), num_of_attributes):
           vert_pos_index = index_array[i + 0]
           vert_positions.append(vert_pos_array[vert_pos_index * 3 + 0])
           vert_positions.append(vert_pos_array[vert_pos_index * 3 + 1])
           vert_positions.append(vert_pos_array[vert_pos_index * 3 + 2])
           
           normal_index = index_array[i + 1]
           normals.append(normal_array[normal_index * 3 + 0])
           normals.append(normal_array[normal_index * 3 + 1])
           normals.append(normal_array[normal_index * 3 + 2])
           
           tex_coord_index = index_array[i + 2]
           tex_coords.append(tex_coord_array[tex_coord_index * 2 + 0])
           tex_coords.append(tex_coord_array[tex_coord_index * 2 + 1])
       # print(vert_positions)
       # print(normals)
       # print(tex_coords)
       
       output = {}

       vert_positions = np.array(vert_positions, dtype=np.float32)
       vert_pos_buffer = QOpenGLBuffer()
       vert_pos_buffer.create()
       vert_pos_buffer.bind()
       vert_pos_buffer.allocate(vert_positions, len(vert_positions) * 4)
       
       normals = np.array(normals, dtype=np.float32)
       normal_buffer = QOpenGLBuffer()
       normal_buffer.create()
       normal_buffer.bind()
       normal_buffer.allocate(normals, len(normals) * 4)
       
       tex_coords = np.array(tex_coords, dtype=np.float32)
       tex_coord_buffer = QOpenGLBuffer()
       tex_coord_buffer.create()
       tex_coord_buffer.bind()
       tex_coord_buffer.allocate(tex_coords, len(tex_coords) * 4)

       vert_buffers = VertexBuffers()
       vert_buffers.vert_pos_buffer = vert_pos_buffer
       vert_buffers.normal_buffer = normal_buffer
       vert_buffers.tex_coord_buffer = tex_coord_buffer
       vert_buffers.amount_of_vertices = int(len(index_array) / 3)
       
       return vert_buffers

def main():
   QApplication.setAttribute(Qt.AA_UseDesktopOpenGL)
   app = QApplication(sys.argv)
   w = Window()
   w.show()
   sys.exit(app.exec_())

if __name__ == "__main__":
   main()

PySide2:

import sys
import numpy as np
from OpenGL import GL as gl
from PySide2.QtWidgets import QApplication, QOpenGLWidget
from PySide2.QtGui import QOpenGLShaderProgram, QOpenGLShader, QOpenGLBuffer
from PySide2.QtGui import QOpenGLTexture, QImage
from PySide2.QtGui import QMatrix4x4, QVector3D, QQuaternion
from PySide2.QtXml import QDomDocument, QDomElement
from PySide2.QtCore import Qt, QFile, QIODevice
from PySide2.QtCore import QTimer, QElapsedTimer

from panda3d.bullet import BulletWorld
from panda3d.core import TransformState, Vec3, Quat, Point3
from panda3d.bullet import BulletBoxShape
from panda3d.bullet import BulletRigidBodyNode

# Assets:
# Cube Texture: https://dl.dropboxusercontent.com/s/tply9ubx3n3ycvv/cube.png
# Cube Model: https://dl.dropboxusercontent.com/s/0aktc37c3nx9iq3/cube.dae
# Plane Texture: https://dl.dropboxusercontent.com/s/3iibsnvyw0vupby/plane.png
# Plane Model: https://dl.dropboxusercontent.com/s/e0wktg69ec3w8pq/plane.dae

class VertexBuffers:
   vertex_pos_buffer = None
   normal_buffer = None
   tex_coord_buffer = None
   amount_of_vertices = None

class Locations:
   mvp_matrix_location = None
   model_matrix_location = None
   normal_matrix_location = None

class Object3D:
   position = QVector3D(0, 0, 0)
   rotation = QVector3D(0, 0, 0)
   scale = QVector3D(1, 1, 1)
   mvp_matrix = QMatrix4x4()
   model_matrix = QMatrix4x4()
   normal_matrix = QMatrix4x4()

   def __init__(self, vert_buffers, locations, texture, world, mass, pos):
       self.vert_pos_buffer = vert_buffers.vert_pos_buffer
       self.normal_buffer = vert_buffers.normal_buffer
       self.tex_coord_buffer = vert_buffers.tex_coord_buffer
       self.amount_of_vertices = vert_buffers.amount_of_vertices
       
       self.mvp_matrix_location = locations.mvp_matrix_location
       self.model_matrix_location = locations.model_matrix_location
       self.normal_matrix_location = locations.normal_matrix_location
       
       self.texture = texture

       self.shape = BulletBoxShape(Vec3(0.5, 0.5, 0.5))
       self.node = BulletRigidBodyNode('Box')

       self.position = pos
       self.mass = mass
       self.node.setMass(self.mass)

       p = Point3(self.position.x(), self.position.y(), self.position.z())
       q = Quat.identQuat()
       s = Vec3(1, 1, 1)

       self.transform = TransformState.make_pos_quat_scale(p, q, s)
       self.node.setTransform(self.transform)

       self.node.addShape(self.shape)
       self.world = world
       self.world.attachRigidBody(self.node)

   def draw(self, program, proj_view_matrix):
       program.bind()

       self.vert_pos_buffer.bind()
       program.setAttributeBuffer(0, gl.GL_FLOAT, 0, 3)
       program.enableAttributeArray(0)

       self.normal_buffer.bind()
       program.setAttributeBuffer(1, gl.GL_FLOAT, 0, 3)
       program.enableAttributeArray(1)

       self.tex_coord_buffer.bind()
       program.setAttributeBuffer(2, gl.GL_FLOAT, 0, 2)
       program.enableAttributeArray(2)

       self.position.setX(self.node.getTransform().pos.x)
       self.position.setY(self.node.getTransform().pos.y)
       self.position.setZ(self.node.getTransform().pos.z)
       hpr = self.node.getTransform().getHpr()
       pandaQuat = Quat()
       pandaQuat.setHpr(hpr)
       quat = QQuaternion(pandaQuat.getX(), pandaQuat.getY(), pandaQuat.getZ(), pandaQuat.getW())
       
       self.model_matrix.setToIdentity()
       self.model_matrix.translate(self.position)
       self.model_matrix.rotate(quat)
       self.model_matrix.scale(self.scale)
       self.mvp_matrix = proj_view_matrix * self.model_matrix
       
       self.normal_matrix = self.model_matrix.inverted()
       self.normal_matrix = self.normal_matrix[0].transposed()
       
       program.bind()
       program.setUniformValue(self.mvp_matrix_location, self.mvp_matrix)
       program.setUniformValue(self.model_matrix_location, self.model_matrix)
       program.setUniformValue(self.normal_matrix_location, self.normal_matrix)
       
       self.texture.bind()

       gl.glDrawArrays(gl.GL_TRIANGLES, 0, self.amount_of_vertices)

class Window(QOpenGLWidget):

   def __init__(self):
       super().__init__()
       self.setWindowTitle("Bullet Physics")
       self.resize(268, 268)

   def initializeGL(self):
       gl.glClearColor(0.2, 0.2, 0.2, 1)
       gl.glEnable(gl.GL_DEPTH_TEST)
       vertShaderSrc = """
           #version 330 core

           in vec4 aPosition;
           in vec4 aNormal;
           in vec2 aTexCoord;

           uniform mat4 uMvpMatrix;
           uniform mat4 uModelMatrix;
           uniform mat4 uNormalMatrix;

           out vec3 vPosition;
           out vec3 vNormal;
           out vec2 vTexCoord;

           void main()
           {
               gl_Position = uMvpMatrix * aPosition;
               vPosition = vec3(uModelMatrix * aPosition);
               vNormal = normalize(vec3(uNormalMatrix * aNormal));
               vTexCoord = aTexCoord;
           }
       """
       fragShaderSrc = """
           #version 330 core

           const vec3 lightColor = vec3(0.8, 0.8, 0.8);
           const vec3 lightPosition = vec3(5.0, 7.0, 2.0);
           const vec3 ambientLight = vec3(0.3, 0.3, 0.3);

           uniform sampler2D uSampler;

           in vec3 vPosition;
           in vec3 vNormal;
           in vec2 vTexCoord;

           void main()
           {
               vec4 color = texture2D(uSampler, vTexCoord);
               vec3 normal = normalize(vNormal);
               vec3 lightDirection = normalize(lightPosition - vPosition);
               float nDotL = max(dot(lightDirection, normal), 0.0);
               vec3 diffuse = lightColor * color.rgb * nDotL;
               vec3 ambient = ambientLight * color.rgb;
               gl_FragColor = vec4(diffuse + ambient, color.a);
           }
       """
       self.program = QOpenGLShaderProgram()
       self.program.addShaderFromSourceCode(QOpenGLShader.Vertex, vertShaderSrc)
       self.program.addShaderFromSourceCode(QOpenGLShader.Fragment, fragShaderSrc)
       self.program.link()
       self.program.bind()
       self.program.bindAttributeLocation("aPosition", 0)
       self.program.bindAttributeLocation("aNormal", 1)
       self.program.bindAttributeLocation("aTexCoord", 2)
       locations = Locations()
       self.program.bind()
       locations.mvp_matrix_location = self.program.uniformLocation("uMvpMatrix")
       locations.model_matrix_location = self.program.uniformLocation("uModelMatrix")
       locations.normal_matrix_location = self.program.uniformLocation("uNormalMatrix")
       self.vert_buffers = self.initVertexBuffers("assets/cube.dae")
       self.proj_view_matrix = QMatrix4x4()
       self.proj_matrix = QMatrix4x4()
       self.view_matrix = QMatrix4x4()
       self.view_matrix.lookAt(
           QVector3D(2, 3, 5),
           QVector3D(0, 0, 0),
           QVector3D(0, 1, 0))
       
       self.texture = QOpenGLTexture(QOpenGLTexture.Target2D)
       self.texture.create()
       self.texture.setData(QImage("assets/cube.png"))
       self.texture.setMinMagFilters(QOpenGLTexture.Linear, QOpenGLTexture.Linear)
       self.texture.setWrapMode(QOpenGLTexture.ClampToEdge)

       self.world = BulletWorld()
       self.world.setGravity(Vec3(0, -9.81, 0))

       self.obj = Object3D(self.vert_buffers, locations, self.texture, self.world, mass=0, pos=QVector3D(0, -3, 0))
       self.obj2 = Object3D(self.vert_buffers, locations, self.texture, self.world, mass=1, pos=QVector3D(0.8, 3, 0))
       
       #self.move_dir = 1 # move direction: 1 - up, -1 - down
       #self.move_speed = 0.002
       
       self.timer = QTimer()
       self.timer.timeout.connect(self.animationLoop)
       self.elapsed_timer = QElapsedTimer()
       self.elapsed_timer.start()
       self.delta_time = 0
       self.timer.start(1000/60)
       
   def animationLoop(self):
       self.delta_time = self.elapsed_timer.elapsed()
       self.elapsed_timer.restart()
       self.world.doPhysics(self.delta_time / 1000)
       self.update()
       
   def paintGL(self):
       gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
       self.proj_view_matrix = self.proj_matrix * self.view_matrix
       self.obj.draw(self.program, self.proj_view_matrix)
       self.obj2.draw(self.program, self.proj_view_matrix)

   def resizeGL(self, w, h):
       gl.glViewport(0, 0, w, h)
       self.proj_matrix.setToIdentity()
       self.proj_matrix.perspective(50, float(w) / float(h), 0.1, 100)
       
   def initVertexBuffers(self, path):
       xml_doc = QDomDocument()
       file = QFile(path)
       if not file.open(QIODevice.ReadOnly):
           print("Failed to open the file: " + path)
       xml_doc.setContent(file)
       file.close()
       
       vert_pos_array = []
       normal_array = []
       tex_coord_array = []
       index_array = []
       
       root = xml_doc.documentElement()
       dae_elem = root.firstChildElement()
       while not dae_elem.isNull():
           if dae_elem.tagName() == "library_geometries":
               geom_elem = dae_elem.firstChildElement()
               if geom_elem.tagName() == "geometry":
                   mesh_elem = geom_elem.firstChildElement()
                   if mesh_elem.tagName() == "mesh":
                       mesh_child_elem = mesh_elem.firstChildElement()
                       while not mesh_child_elem.isNull():
                           float_array_elem = mesh_child_elem.firstChildElement()
                           str_array = float_array_elem.firstChild().toText().data().split(" ")
                           if mesh_child_elem.attribute("id").endswith("-mesh-positions"):
                               vert_pos_array = list(map(float, str_array))
                           if mesh_child_elem.attribute("id").endswith("-mesh-normals"):
                               normal_array = list(map(float, str_array))
                           if mesh_child_elem.attribute("id").endswith("-mesh-map-0"):
                               tex_coord_array = list(map(float, str_array))
                           if mesh_child_elem.tagName() == "triangles" or mesh_child_elem.tagName() == "polylist":
                               p_child_elem = mesh_child_elem.firstChildElement()
                               while not p_child_elem.isNull():
                                   if p_child_elem.tagName() == "p":
                                       str_indices = p_child_elem.firstChild().toText().data().split(" ")
                                       index_array = list(map(int, str_indices))
                                   p_child_elem = p_child_elem.nextSiblingElement()
                           mesh_child_elem = mesh_child_elem.nextSiblingElement()
           dae_elem = dae_elem.nextSiblingElement()
       # print(vert_pos_array)
       # print(normal_array)
       # print(tex_coord_array)
       # print(index_array)
       
       num_of_attributes = 3
       vert_positions = []
       normals = []
       tex_coords = []
       for i in range(0, len(index_array), num_of_attributes):
           vert_pos_index = index_array[i + 0]
           vert_positions.append(vert_pos_array[vert_pos_index * 3 + 0])
           vert_positions.append(vert_pos_array[vert_pos_index * 3 + 1])
           vert_positions.append(vert_pos_array[vert_pos_index * 3 + 2])
           
           normal_index = index_array[i + 1]
           normals.append(normal_array[normal_index * 3 + 0])
           normals.append(normal_array[normal_index * 3 + 1])
           normals.append(normal_array[normal_index * 3 + 2])
           
           tex_coord_index = index_array[i + 2]
           tex_coords.append(tex_coord_array[tex_coord_index * 2 + 0])
           tex_coords.append(tex_coord_array[tex_coord_index * 2 + 1])
       # print(vert_positions)
       # print(normals)
       # print(tex_coords)
       
       output = {}

       vert_positions = np.array(vert_positions, dtype=np.float32)
       vert_pos_buffer = QOpenGLBuffer()
       vert_pos_buffer.create()
       vert_pos_buffer.bind()
       vert_pos_buffer.allocate(vert_positions, len(vert_positions) * 4)
       
       normals = np.array(normals, dtype=np.float32)
       normal_buffer = QOpenGLBuffer()
       normal_buffer.create()
       normal_buffer.bind()
       normal_buffer.allocate(normals, len(normals) * 4)
       
       tex_coords = np.array(tex_coords, dtype=np.float32)
       tex_coord_buffer = QOpenGLBuffer()
       tex_coord_buffer.create()
       tex_coord_buffer.bind()
       tex_coord_buffer.allocate(tex_coords, len(tex_coords) * 4)

       vert_buffers = VertexBuffers()
       vert_buffers.vert_pos_buffer = vert_pos_buffer
       vert_buffers.normal_buffer = normal_buffer
       vert_buffers.tex_coord_buffer = tex_coord_buffer
       vert_buffers.amount_of_vertices = int(len(index_array) / 3)
       
       return vert_buffers

def main():
   QApplication.setAttribute(Qt.AA_UseDesktopOpenGL)
   app = QApplication(sys.argv)
   w = Window()
   w.show()
   sys.exit(app.exec_())

if __name__ == "__main__":
   main()