[Visualpython-users] Animation Capture

[Bruce P. <bap...@te...>]

At 07:27 PM 10/24/2004, you wrote:


>    1. RE: Bitmap Rendering (Joel Kahn)
>--__--__--
>
>Message: 1
>Date: Sun, 24 Oct 2004 03:12:44 -0700 (PDT)
>From: Joel Kahn <jj...@ya...>
>To: vis...@li...
>Subject: [Visualpython-users] RE: Bitmap Rendering
>
>Bruce Peterson described a method of using a screen
>capture utility from the Image Library to grab a
>series of frames that can be later hooked up to make
>an animation. I'm wondering if anyone has available
>any actual code implementing what he laid out. With my
>still-limited knowledge, I'm not sure how well I could
>put it all together just from Bruce's prose; I need to
>know more about exactly which commands to use and how
>to use them. Plus, of course, we all want to avoid
>wheel re-invention when we can. :-)
>
>Joel

Joel
    I've attached some sample code using the VPython ball bounce example. A 
number of items are hard coded in -- like the directories -- that you may 
wish to change before testing it.
=========================code begins ===========================
import win32gui
import Image
from visual import *
from os.path import *

def animate_something():
     strTitle="Demo Screen Capture"
     strSaveFile="C:/temp/capfile.jpg"
     demoscr=display(title=strTitle,width=800, height=600)
     demoscr.select()
     blnQuit=False
     blnCapture=False
     framecount=0

     side = 4.0
     thk = 0.3
     s2 = 2*side - thk
     s3 = 2*side + thk
     wallR = box (pos=( side, 0, 0), length=thk, 
height=s2,  width=s3,  color = color.red)
     wallL = box (pos=(-side, 0, 0), length=thk, 
height=s2,  width=s3,  color = color.red)
     wallB = box (pos=(0, -side, 0), length=s3,  height=thk, 
width=s3,  color = color.blue)
     wallT = box (pos=(0,  side, 0), length=s3,  height=thk, 
width=s3,  color = color.blue)
     wallBK = box(pos=(0, 0, -side), length=s2,  height=s2,  width=thk, 
color = (0.7,0.7,0.7))

     ball = sphere (color = color.green, radius = 0.4)
     ball.mass = 1.0
     ball.p = vector (-0.15, -0.23, +0.27)

     side = side - thk*0.5 - ball.radius

     dt = 0.5
     t=0.0
     while not blnQuit:
         if demoscr.kb.keys:
             ukey=demoscr.kb.getkey()
             if ukey=='Q':
                 blnQuit=True
             elif ukey=='C':
                 blnCapture=not blnCapture


         t = t + dt
         ball.pos = ball.pos + ball.p*(dt/ball.mass)
         if not (side > ball.x > -side):
             ball.p.x = -ball.p.x
         if not (side > ball.y > -side):
             ball.p.y = -ball.p.y
         if not (side > ball.z > -side):
             ball.p.z = -ball.p.z

         if blnCapture:
             rate(1)
             framecount+=1
             my_scrndump(strTitle,demoscr,strSaveFile,framecount)
         rate(99)

     demoscr.visible=False



def my_scrndump(wintitle,actdisplay,svfile,frmno):
         try:
     # built-in driver (1.1.3 and later)
             grabber = Image.core.grabscreen
         except AttributeError:
             return None

         winhndl=win32gui.FindWindow("wglWindowC",wintitle)
         scrntuple=win32gui.GetWindowRect(winhndl)
         actdisplay.select()
         imsize,imdata=grabber()
         imtmp=Image.fromstring("RGB",imsize,imdata,"raw","BGR",(imsize[0]*3+3) 
& -4,-1)

         imtmp=imtmp.crop(scrntuple)
         fntmp=svfile
##        print "base name for file ",fntmp
         fndir=dirname(fntmp)
         fnbase=basename(fntmp)[:-4]
         fntype=basename(fntmp)[-4:]
         fncount=str('%06i' % frmno)
         fn=fndir + '/' + fnbase +fncount + fntype
##        print fn
         try:
             imtmp.save(fn)
         except:
             fn=fn[:-3]+"Jpeg"
             imtmp.save(fn)
         return None

if __name__=='__main__':
     animate_something()

===============================code ends =========================



Bruce Peterson
425 466 7344