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pythonopenglblenderpyopenglwavefront

PyOpenGL how do I import an obj file?

import pygame
import OpenGL
from pygame.locals import *
from OpenGL.GL import *
from OpenGL.GLU import *
import pywavefront


scene = pywavefront.Wavefront('Handgun_obj.obj')

vertices =(
    (1,-1,-1),
    (1,1,-1),
    (-1,1,-1),
    (-1,-1,-1),
    (1,-1,1),
    (1,1,1),
    (-1,-1,1),
    (-1,1,1),
    )

edges = (
    (0,1),
    (0,3),
    (0,4),
    (2,1),
    (2,3),
    (2,7),
    (6,3),
    (6,4),
    (6,7),
    (5,1),
    (5,4),
    (5,7)
    )

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),
    (3,2,7,6),
    (6,7,5,4),
    (4,5,1,0),
    (1,5,7,2),
    (4,0,3,6)
    )



def Cube():
    glBegin(GL_QUADS)
    for surface in surfaces:
        x = 0
        for vertex in surface:
            x += 1
            glColor3fv(colors[x])
            glVertex3fv(vertices[vertex])
    glEnd()

    glBegin(GL_LINES) #tells OpenGL dass code erhalten wird der als line-drawing code benutzt wird
    for edge in edges:
        for vertex in edge:
            glVertex3fv(vertices[vertex])
    glEnd()

def main():
        pygame.init()
        display = (800, 600)
        pygame.display.set_mode(display, DOUBLEBUF | OPENGL)
        gluPerspective(45, (display[0] / display[1]), 1, 500.0)
        glTranslatef(0.0, 0.0, -10)

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

                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_LEFT:
                        glTranslatef(-0.5,0,0)
                    if event.key == pygame.K_RIGHT:
                        glTranslatef(0.5,0,0)
                    if event.key == pygame.K_UP:
                        glTranslatef(0,1,0)
                    if event.key == pygame.K_DOWN:
                        glTranslatef(0,-1,0)


            glRotatef(1, 5, 1, 1)
            glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
            Cube()
            pygame.display.flip()
            pygame.time.wait(10)

main()

Now I want to add the scene into my window with the cube or replace it whatever

Could someone tell me how to accomplish that?

So I guess I have to add new vertices from my scene right?

I want to add the obj now to learn how to import blender models into a game

Solution

  • Set the keyword argument collect_faces = True, when you read the Wavefront .obj file. That causes that triangle face data are collected for every mesh.:
    (See PyWavefront)

    scene = pywavefront.Wavefront('Handgun_obj.obj', collect_faces=True)

    Compute the scene box. The vertices are contained in scene.vertices. Each vertex is tuple with 3 components (x, y, z coordinate):

    scene_box = (scene.vertices[0], scene.vertices[0])
for vertex in scene.vertices:
    min_v = [min(scene_box[0][i], vertex[i]) for i in range(3)]
    max_v = [max(scene_box[1][i], vertex[i]) for i in range(3)]
    scene_box = (min_v, max_v)

    Compute a translation, that moves the center of the object to the origin and a scale, that scales the object to a defined size (scaled_size):

    scene_trans    = [-(scene_box[1][i]+scene_box[0][i])/2 for i in range(3)]

scaled_size    = 5
scene_size     = [scene_box[1][i]-scene_box[0][i] for i in range(3)]
max_scene_size = max(scene_size)
scene_scale    = [scaled_size/max_scene_size for i in range(3)]

    Each scene consists of meshes (scene.mesh_list) and each mesh has triangle faces (mesh.faces). Each fac is an array of 3 indies which refer to the array of vertices [scene.vertices]. Crate a function which sets the scale and translation and draw the model in nested loops:

    def Model():
    glPushMatrix()
    glScalef(*scene_scale)
    glTranslatef(*scene_trans)

    for mesh in scene.mesh_list:
        glBegin(GL_TRIANGLES)
        for face in mesh.faces:
            for vertex_i in face:
                glVertex3f(*scene.vertices[vertex_i])
        glEnd()

    glPopMatrix()

    See also PyGame and OpenGL immediate mode (Legacy OpenGL)

    Minimal example (Stanford bunny):

    repl.it/@Rabbid76/pygame-opengl-wavefront-obj

    import pygame
import OpenGL
from pygame.locals import *
from OpenGL.GL import *
from OpenGL.GLU import *
import pywavefront

scene = pywavefront.Wavefront('bunny.obj', collect_faces=True)

scene_box = (scene.vertices[0], scene.vertices[0])
for vertex in scene.vertices:
    min_v = [min(scene_box[0][i], vertex[i]) for i in range(3)]
    max_v = [max(scene_box[1][i], vertex[i]) for i in range(3)]
    scene_box = (min_v, max_v)

scene_size     = [scene_box[1][i]-scene_box[0][i] for i in range(3)]
max_scene_size = max(scene_size)
scaled_size    = 5
scene_scale    = [scaled_size/max_scene_size for i in range(3)]
scene_trans    = [-(scene_box[1][i]+scene_box[0][i])/2 for i in range(3)]

def Model():
    glPushMatrix()
    glScalef(*scene_scale)
    glTranslatef(*scene_trans)

    for mesh in scene.mesh_list:
        glBegin(GL_TRIANGLES)
        for face in mesh.faces:
            for vertex_i in face:
                glVertex3f(*scene.vertices[vertex_i])
        glEnd()

    glPopMatrix()

def main():
        pygame.init()
        display = (800, 600)
        pygame.display.set_mode(display, DOUBLEBUF | OPENGL)
        gluPerspective(45, (display[0] / display[1]), 1, 500.0)
        glTranslatef(0.0, 0.0, -10)

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

                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_LEFT:
                        glTranslatef(-0.5,0,0)
                    if event.key == pygame.K_RIGHT:
                        glTranslatef(0.5,0,0)
                    if event.key == pygame.K_UP:
                        glTranslatef(0,1,0)
                    if event.key == pygame.K_DOWN:
                        glTranslatef(0,-1,0)

            glRotatef(1, 5, 1, 1)
            glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)

            glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)
            Model()
            glPolygonMode(GL_FRONT_AND_BACK, GL_FILL)

            pygame.display.flip()
            pygame.time.wait(10)

main()