On 19 Nov 1997, Nieminen Mika wrote:

> Roland Mas (bob### [at] casimirrezelenstfr) wrote:
> : Even two ones!
> : 1. The easier one: buy a computer. I did it recently, and was _really_
> : surprised how much difference a P200 MMX had in rendering speed compare
d
> : to a 486DX2/66 with 24 Mb RAM.
> : 2. The cheaper one: optimize your scenes. I used to do it (and still do
,
> : of course), and thus saved _lots_ of rendering time. Use bounding boxes
> : and automatic bounding. Use simple texture until the final rendering. S
ame
> : for the atmospheric effects.
> 
>   3. Avoid reflection and refraction in the same texture if possible, or
> at least until the final rendering. If an object is both reflective and
> refractive, the rendering time explodes. Alternatively use a smaller rend
ering
> quality until final rendering.
>   4. If you have really complicated objects, replace them with a bounding
> object until final rendering.
> 
>   There are some things that are really slow, but that you have to test a
gain
> and again until you find the correct parameters, like the atmosphere, som
e
> halo types, etc. I don't know how to speed this up, and it has caused me
> a lot of problems (atmosphere looks a _lot_ different in a 64x48 sized
> image than in a 800x600 sized)
> 
> --

>                                                               - Warp. -
> 
> 

You can make use of #declare and #ifdef to easily switch your scene from 
a quick mode to render while you're working on it to a more complete one 
for something like an overnight render.  Refraction is really slow and I 
do a lot of stuff with glass.  Put your simple preview declarations in a 
section that gets activated if a certain symbol is defined ("fast" in my 
example below) and the real ones in a section that gets called if the 
symbol isn't defined.

Try something like:

// (Put a line like this near the top of your file:)
#declare fast = 1    // comment this line out for the full render

#ifdef (fast)   // done only if fast is on
  plane { a simple plane just to show where it is }
  #declare T1 = texture{pigment{Blue}}  // simple textures only
#else           // done only when fast isn't on
  plane { your real, big, messy floor pattern if you use one }
  #declare T1 = texture{ Throw all your refraction, reflection, etc. in h
ere}
  sky_sphere { clouds and any other messy stuff }
  other_optional_stuff
#end            // put sections like this whereever you need them 

That's probably enough to give the idea.  I use a 486DX2-66 with 24 megs 
and 256K cache myself.  Mostly I use shortcuts like those above and work 
in 320x200 mode.  When I get things about the way I want them I start a 
640x480 AA render and go to bed or to work.  6 hours or more isn't 
uncommon for that machine.  You can also build a cache of files to be 
rendered unattended sometime like overnight if you're working on several 
things at once. 

It's slow but I still enjoy it.  Have fun.  Alan Corey

Post a reply to this message

Alan Corey wrote:
> 
> On 19 Nov 1997, Nieminen Mika wrote:
> 
> You can make use of #declare and #ifdef to easily switch your scene from
> a quick mode to render while you're working on it to a more complete one
> for something like an overnight render.  Refraction is really slow and I
> do a lot of stuff with glass.  Put your simple preview declarations in a
> section that gets activated if a certain symbol is defined ("fast" in my
> example below) and the real ones in a section that gets called if the
> symbol isn't defined.

> That's probably enough to give the idea.  I use a 486DX2-66 with 24 megs
> and 256K cache myself.  Mostly I use shortcuts like those above and work
> in 320x200 mode.  When I get things about the way I want them I start a
> 640x480 AA render and go to bed or to work.  6 hours or more isn't
> uncommon for that machine.  You can also build a cache of files to be
> rendered unattended sometime like overnight if you're working on several
> things at once.

I also have a 486 with 24 megs ram and 256k cache.  I did all of the
above, but also I would generally do my test renders in 160x100.  Still,
it could take 30 mins or so for a scene, but there just wasn't any way
around it.  But, I use a lot of atmospherics, and we all know how slow
they are.  I had one other trick up my sleeve though.  I would use a
shell internet account at night when almost no one else was logged on.

One trick I had to speed up rendering was instead of useing procedural
textures, I used image maps.  I got those image maps by putting the
camera right above a plane with the procedural texture I wanted, and
then rendering it at a high res.  It help a bit, unless your real hold
up is atmospherics.

In the end, you probably will need to just break down and buy a new
machine.  A pentium 200 mmx MB, chip, and 32 megs of ram will only cost
you about US$300.  I bought a whole new computer pent 200 mmx, 32 megs
ram, 12x cd-rom, SB AWE64, 4 meg video card for a hair over US$800.  I
reused my old 2.5 gig hd and network card and off I went.

And finnally look at it this way, at least you aren't using a 386sx with
no fpu like I started out on.  I had problems trying to get a text
editor to load my 2 meg .pov files, let alone rendering, which
frequently would take all night at a test resolution.  Large files could
take days.

Post a reply to this message