|  |  | 
|  |  |  |  | 
|  |  | 
|  |  | 
|  |  |  |  | 
|  |  | 
|  |  | 
|  |  | CLipka's Radiosity Voodoo recommends that pretrace_start be a power of 2
multiple of pretrace_end, and that pretrace_end translate to one pixel.
Calculating the pixel size is easy enough, but deriving a good pretrace_start
from that over various image sizes requires real math, so I incorporated a
formula into one of my include files so I wouldn't have to figure it out each
time.
Last night, I decided to extract this into a stand-alone macro.  Breathe easy;
it allows you to ease up on the pretrace_end recommendation.  I hope you find it
useful.
 Post a reply to this message
 Attachments:
 Download 'radiosity-pretrace.zip' (4 KB)
 
 
 |  | 
|  |  | 
|  |  | 
|  |  |  |  | 
|  |  | 
|  |  | 
|  |  | On 17-1-2014 0:58, Cousin Ricky wrote:
> Last night, I decided to extract this into a stand-alone macro.  Breathe easy;
> it allows you to ease up on the pretrace_end recommendation.  I hope you find it
> useful.
>
Thanks a lot. IT certainly is useful. I am going to integrate it in my 
scenes.
Thomas
 Post a reply to this message
 |  | 
|  |  | 
|  |  | 
|  |  |  |  | 
|  |  | 
|  |  | 
|  |  | "Cousin Ricky" <rickysttATyahooDOTcom> wrote:
> CLipka's Radiosity Voodoo recommends that pretrace_start be a power of 2
> multiple of pretrace_end, and that pretrace_end translate to one pixel.
> Calculating the pixel size is easy enough, but deriving a good pretrace_start
> from that over various image sizes requires real math, so I incorporated a
> formula into one of my include files so I wouldn't have to figure it out each
> time.
>
> Last night, I decided to extract this into a stand-alone macro.  Breathe easy;
> it allows you to ease up on the pretrace_end recommendation.  I hope you find it
> useful.
There are errors in the documentation.  I pulled an _Of Pandas and People_[1]
and missed some sentences in my global search and replace.  (Funny thing is I
/remember/ proofreading it.  That's why writers never proofread their own work.)
 The corrected files are attached.
________________________
[1] See Kitzmiller v. Dover.
 Post a reply to this message
 Attachments:
 Download 'radiosity-pretrace.zip' (4 KB)
 
 
 |  | 
|  |  | 
|  |  | 
|  |  |  |  | 
|  |  | 
|  |  | 
|  |  | 
> CLipka's Radiosity Voodoo recommends that pretrace_start be a power of 2
> multiple of pretrace_end, and that pretrace_end translate to one pixel.
> Calculating the pixel size is easy enough, but deriving a good pretrace_start
> from that over various image sizes requires real math, so I incorporated a
> formula into one of my include files so I wouldn't have to figure it out each
> time.
>
> Last night, I decided to extract this into a stand-alone macro.  Breathe easy;
> it allows you to ease up on the pretrace_end recommendation.  I hope you find it
> useful.
>
The formulas are prety simple:
pretrace_end 1/image_width // stop at 1 pixel block
pretrace_start 64/image_width // start with 64 pixels blocks
Those will have the pretrace start at 64 pixels and end at 1 pixel 
blocks for any resolution for a total of 7 pretrace steps.
image_hight is unimportant and must be ignored. The size of the pretrace 
tiles is strictly a fraction of the horizontal image of your image.
Alain
 Post a reply to this message
 |  | 
|  |  | 
|  |  | 
|  |  |  |  | 
|  |  | 
|  |  | 
|  |  | Alain <kua### [at] videotron ca> wrote:
> The formulas are prety simple:
>
> pretrace_end 1/image_width // stop at 1 pixel block
> pretrace_start 64/image_width // start with 64 pixels blocks
Why 64?  Why not 32 or 128?  My formula takes the size of the image into
account.
> image_hight is unimportant and must be ignored. The size of the pretrace
> tiles is strictly a fraction of the horizontal image of your image.
No, it goes by whichever is the larger dimension.  Try it. Post a reply to this message
 |  | 
|  |  | 
|  |  | 
|  |  |  |  | 
|  |  | 
|  |  | 
|  |  | Am 18.01.2014 00:01, schrieb Cousin Ricky:
> There are errors in the documentation.  I pulled an _Of Pandas and People_[1]
> and missed some sentences in my global search and replace.
> ________________________
> [1] See Kitzmiller v. Dover.
Duh, that was a difficult one... had to watch the Nova documentary to 
get it. (Highly recommended viewing, BTW!)
 Post a reply to this message
 |  | 
|  |  | 
|  |  | 
|  |  |  |  | 
|  |  |