Hi folks,

I'm trying to implement the falling cloth idea to do an animation. I
thought, to make things easier, I'd investigate persistent variables.
Unfortunately I must be missing something.

I've built a small test scene to show how I think I should do it, but
parsing the second frame I get a "Cannot assign uninitialized
identifier" error where I redefine the variable 'Centre' which should
persist but doen't appear to.

I'm using Megapov 0.5a.

Any help would be appreciated.

Bye for now,
	Mike Andrews.

// pv_test.pov start

#version unofficial MegaPov 0.5;

global_settings { 
  max_trace_level 10
  assumed_gamma 1
}

background { color rgb 0.5/<15,sqrt(15),1> }
                       
light_source {
	0*x
	colour rgb <1,.97,.95>
	translate vnormalize(<-2.5,2.1,-1>)*1.5e4
}

plane { y, 0 pigment { rgb 0.4 } }

#if (frame_number = 1)

  #declare Centre = <0,10,0>;
  
#else

  #declare Centre = Centre + 5*y;

#end

sphere { Centre, 10 pigment { rgb y } }

camera {
	up y
	right x*image_width/image_height
	location  <-30, 10, -80>
	direction <0.0, 0.0, 1>
	angle     45
	look_at   0.5*Centre
}

// pv_test.pov end

; persist.ini start

Persistent_Animation=on
Final_Frame=10

Width=384
Height=512
Antialias=Off

; persist.ini end

Post a reply to this message

Michael Andrews <M.C### [at] readingacuk> wrote:

> Hi folks,
> 
> I'm trying to implement the falling cloth idea to do an animation. I
> thought, to make things easier, I'd investigate persistent variables.
> Unfortunately I must be missing something.
> 
Look no further, it's a bug introduced in 0.5a.

If you have access to a compiler and the sources you can fix it by
moving this block of code at line 1695 in povray.c in function
init_frame_vars():

  /* NK persist - Nov 1999 */
  alreadyInitializedSymTables = 0;
  /* ---- */
to the function init_vars(), also in povray.c, doesn't matter where.

Best regards,

Smellenbergh


-- 
e-mail:sme### [at] skynetbe

http://users.skynet.be/smellenbergh

Post a reply to this message

smellenbergh wrote:
> 
> Michael Andrews <M.C### [at] readingacuk> wrote:
> 
> > Hi folks,
> >
> > I'm trying to implement the falling cloth idea to do an animation. I
> > thought, to make things easier, I'd investigate persistent variables.
> > Unfortunately I must be missing something.
> >
> Look no further, it's a bug introduced in 0.5a.

Whew! That's a relief, I thought I was being even more stupid than
normal ...

> 
> If you have access to a compiler and the sources you can fix it by
> moving this block of code at line 1695 in povray.c in function
> init_frame_vars():
> 
>   /* NK persist - Nov 1999 */
>   alreadyInitializedSymTables = 0;
>   /* ---- */
> to the function init_vars(), also in povray.c, doesn't matter where.

Has anyone figured out all the necessaries for building the GUI Megapov
version using the Cygnus or Mingw32 compilers? I haven't heard anything
recently but I recall that a couple fo people were working on this a
while back. I was going to try myself, but others seemed to be further
along than me so I left them to it ... 

> 
> Best regards,
> 
> Smellenbergh
> 
> --
> e-mail:sme### [at] skynetbe
> 
> http://users.skynet.be/smellenbergh

Thanks for the reply,
	Mike Andrews.

Post a reply to this message