Peter Popov <pet### [at] vipbg> wrote:

>On Mon, 29 Jul 2002 00:32:08 -0500, Richard Morehouse
><rmo### [at] coxnet> wrote:
>
>>can anyone help?
>
>You've taken a lightly wrong path, Richard. Not that it won't get you
>where you want, it's just that you'll get there *very* slow.
>

>Before you go on reading, please revise the radiosity section in the
>manual, especially "always_sample", "save_file" and "load_file".
>
>Now, if you want to have realistic render times with radiosity and
>reflection or refraction, there is a trick most people do. Basically
>the idea is to calculate radiosity first, then render
>reflection/refraction. This is done in two steps. First, remove all
>reflection, transparency and refraction from your objects, and render
>the scene with:
>
>always_sample on 
>save_file "radiosity_file.dat"
>
I am still a bit of a noobie at this so i will have a lot of
questions. 

how would I change the glass objects?

how does colored glass affect this?

what about metal objects? I use quite a lot of the Polished_Chrome
texture

and water?

do i need to change any other finish statements? ie: finish {shiny}


>This will calculate the radiosity contribution of all objects,
>including reflective and refractive ones, without going through the
>pain of including reflection and refraction in the render times. As a
>bonus, this render can be done using lower image resolution settings
>(no anti-aliasing and half the height and width).
>
>Then, on the second stage, bring back your transparency, refraction
>and reflection and use these settings:
>
>always_sample off 
>load_file "radiosity_file.dat" 
>preview_start 1 preview_end 1
>
>This will load the radiosity data already calculated and will not
>calculate any more radiosity samples, which is the idea (it is very
>slow with reflection and refraction). Render at normal resolution,
>anti-aliasing and all.
so the first render is a throwaway just to get the radiosity data?
>
>This same trick is also applicable when you want to continue a trace
>with radiosity - save the radiosity date in the first stage, then
>start the real render using the second settings - you can continue
>that render as often as you want to.

could i use an ini file to do both renders one after the other?


>
>If I got anything wrong, someone please correct me before Richard
>starts another month-long render..
my last month long render was done on a much slower machine.  100mhz
pentium 32mb ram. vs 400mhz k6-2 w 256mb ram. big difference. 

in addition to sharing the machine with my wife I have a mischievious
toddler who likes to turn the computer off when I am not looking. and
we have alot of power outages due to weather this time of year so
anything helps :)

after my first post i started the render again without area lights.
this is making a big difference in render time. 

is the difference in quality significant enough with area lights to
make it worthwhile. ?

>
>Good luck!

Thank you Peter

Richard

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