view.orientation slow

[ivan866]

v.0.6.8 view.orientation seems to cache the whole data when dealing with large datasets, thus yielding a long delay before showing the Tk window

[thomas-haslwanter]

hmm, I have noticed that it is slow. But matplotlib seems to be a bit limited with animations, and using the animation.FuncAnimation was the only way I thought I could do it. Do you have any ideas how else to do it?

[ivan866]

Probably should use OpenGL surfaces and smarter chunked caching, anyhow this is how 3D plots are done in R.

[thomas-haslwanter]

I have played around a bit with PyOpenGL, but still have a few problems. Do you have any experience with OpenGL?

[ivan866]

Usually using OpenGL involves these steps: getting GPU context determining array of vertices constructing them into triangles according to chosen winding rule sending them to render

Pls check my comments in Closed issues #10, #9, #15 section.

[thomas-haslwanter]

Hi Ivan,

Maybe you can help me with this:

The attached program does a visualization with OpenGL (not the quaternions yet, but that is a small problem) - but I would really like to view the scene from higher up and right. Any idea what I would have to do?

Thank,

thomas

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Prof. (FH) PD Dr. Thomas Haslwanter School of Applied Health and Social Sciences University of Applied Sciences Upper Austria FH OÖ Studienbetriebs GmbH Garnisonstraße 21 4020 Linz/Austria Tel.: +43 (0)5 0804 -52170 Fax: +43 (0)5 0804 -52171 E-Mail: Thomas.Haslwanter@fh-linz.at Web: bim.fh-linz.at or work.thaslwanter.at

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From: Ivan notifications@github.com Sent: Sunday, December 24, 2017 4:08 PM To: thomas-haslwanter/scikit-kinematics Cc: Haslwanter Thomas; Comment Subject: Re: [thomas-haslwanter/scikit-kinematics] view.orientation slow (#14)

Usually using OpenGL involves these steps: getting GPU context determining array of vertices constructing them into triangles according to chosen winding rule sending them to render

Pls check my comments in Closed issues #10https://github.com/thomas-haslwanter/scikit-kinematics/issues/10, #9https://github.com/thomas-haslwanter/scikit-kinematics/issues/9 section.

- You are receiving this because you commented. Reply to this email directly, view it on GitHubhttps://github.com/thomas-haslwanter/scikit-kinematics/issues/14#issuecomment-353789145, or mute the threadhttps://github.com/notifications/unsubscribe-auth/ABdaRZZsWNGNC6A2mqVGf8SP0H1Tvjsdks5tDmj8gaJpZM4RIguO.

import pygame import numpy as np from pygame.locals import *

from OpenGL.GL import from OpenGL.GLU import

import numpy as np import pandas as pd import abc

To ensure that the relative path works

import os import sys dir_name = os.path.dirname(file) sys.path.append(os.path.realpath(os.path.join(dir_name, "..")))

delta = 0.01 verticies = ( (0, -0.2, -delta), (0, 0.2, -delta), (0.6, 0, -delta), (0, -0.2, delta), (0, 0.2, delta), (0.6, 0, delta), )

edges = ( (0,1), (0,2), (0,3), (1,2), (1,4), (2,5), (3,4), (3,5), (4,5), )

colors = ( (1,0,0), (0,1,0), (0,0,1), (0,1,0), (1,1,1), (0,1,1), (1,0,0), (0,1,0), (0,0,1), (1,0,0), (1,1,1), (0,1,1), )

surfaces = ( (0,1,2), (3,4,5), (0,1,3,4), (1,4,2,5), (0,3,2,5) )

axes_endpts = np.array( [[-1, 0, 0], [ 1, 0, 0], [ 0, -1, 0], [ 0, 1, 0], [ 0, 0, -1], [ 0, 0, 1]])

axes = ( (0,1), (2,3), (4,5) )

def draw_axes(): glBegin(GL_LINES) glColor3fv(colors[4])

glLineWidth('+5')

for line in axes:
    for vertex in line:
        glVertex3fv(axes_endpts[vertex])
glEnd()

def Cube(): glBegin(GL_TRIANGLES)

for vertex in surfaces[1]:
    glColor3fv(colors[4])
    glVertex3fv(verticies[vertex])

for vertex in surfaces[0]:
    glColor3fv(colors[0])
    glVertex3fv(verticies[vertex])
#x = 0
#for surface in surfaces:
    #for vertex in surface:
        #x+=1
        #glColor3fv(colors[np.mod(x,11)])
        #glVertex3fv(verticies[vertex])

glEnd()

glBegin(GL_LINES)
glColor3fv(colors[2])
for edge in edges:
    for vertex in edge:
        glVertex3fv(verticies[vertex])

glEnd()

''' '''

def main():

my_sensor = XSens(in_file=r'..\tests\data\data_xsens.txt')

pygame.init()
display = (800,600)
pygame.display.set_mode(display, DOUBLEBUF|OPENGL)

gluPerspective(45, (display[0]/display[1]), 0.1, 50.0)
glTranslatef(0.0,0.0, -5)

angle = 0
while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            quit()

    glLoadIdentity()
    angle += 1
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
    glEnable(GL_DEPTH_TEST)
    glMatrixMode(GL_PROJECTION)
    glPushMatrix()
    glRotatef(angle, 1, 2, 1)
    Cube()
    glPopMatrix()
    draw_axes()
    pygame.display.flip()
    pygame.time.wait(10)

main()

[ivan866]

The preliminary result is that by using glRotatef you rotate the camera, not the model. Try placing the glPopMatrix line right after the draw_axes(). You'll see what is actually happening. That is not the triangle which rotates, but the viewport.

What you need to do is find a function which takes your model and rotates it like a 3D object in space, and just tilt your camera once beforehand.

[ivan866]

Have tested Orientation_OGL. Works like charm.
Except that current video mode cannot drop or redraw before previous frame rendered completely, thus it seems impossible to animate at a frame rate higher than your screen's refresh, which is 60 Hz for a common LCD.