[PyOpenGL-Users] clipping? far image question

[Astan C. <st...@al...>]

Hi,
I am trying to see how big/far my objects can be in (py)opengl. I 
thought there was no limit and everything should be visible but a sphere 
with radius 70 and the camera is 150 units away, only half of the sphere 
is visible. What is causing this? Is it plane clipping? How do I set it 
so that it renders regardless of distance and size? Im not after 
performance so I dont care if it is slow.
Cheers
Astan
PS: Here is the code I use:


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

rtri = 0.0
dlBody = None

def resize((width, height)):
    if height==0:
        height=1
    glViewport(0, 0, width, height)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(45, 1.0*width/height, 0.1, 100.0)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

def init():
    global dlBody
    glShadeModel(GL_SMOOTH)
    glClearColor(0.0, 0.0, 0.0, 0.0)
    glClearDepth(1.0)
    glEnable(GL_DEPTH_TEST)
    glDepthFunc(GL_LEQUAL)
    glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_FASTEST)
    glEnable(GL_COLOR_MATERIAL)
    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)
    radius = 70
    color = (0.7,1.5,0.5)
    dlBody = glGenLists(1)
    glNewList(dlBody,GL_COMPILE)
    Sphere = gluNewQuadric()
    gluSphere(Sphere, radius, 32, 32)
    gluQuadricNormals(Sphere, GLU_SMOOTH)
    gluQuadricDrawStyle(Sphere, GLU_FILL)   
    glEndList()
   
def draw():
    global dlBody
    global rtri
    if dlBody:
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glLoadIdentity()       
        glTranslatef(0.0,0.0,-150)
        glPushMatrix()
        glColor3f(0.7,1.5,0.5)
        glRotatef(10,1,0,0)
        glRotatef(rtri, 0.0, 1.0, 0.0)
        glCallList(dlBody)
        glPopMatrix()
        rtri+=1
        if rtri == 360:
            rtri = 0

def main():

    video_flags = OPENGL|DOUBLEBUF
   
    pygame.init()
    pygame.display.set_mode((640,480), video_flags)

    resize((640,480))
    init()

    frames = 0
    ticks = pygame.time.get_ticks()
    while 1:
        event = pygame.event.poll()
        if event.type == QUIT or (event.type == KEYDOWN and event.key == 
K_ESCAPE):
            break
       
        draw()
        pygame.display.flip()
        frames = frames+1

    print "fps:  %d" % ((frames*1000)/(pygame.time.get_ticks()-ticks))
    pygame.quit()

if __name__ == '__main__': main()

-- 
"Formulations of number theory: Complete, Consistent, Non-trivial. Choose two."


Animal Logic
http://www.animallogic.com

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