POV-Ray : Newsgroups : povray.documentation.inbuilt : Documentation for blend_mode and blend_gamma? Server Time: 27 Jun 2019 03:58:09 GMT
  Documentation for blend_mode and blend_gamma? (Message 1 to 3 of 3)  
From: William F Pokorny
Subject: Documentation for blend_mode and blend_gamma?
Date: 18 Nov 2016 20:43:52
Message: <582f6808$1@news.povray.org>
Christoph mentioned blend_mode elsewhere today. To my knowledge the two 
options blend_mode and blend_gamma are not yet in our documentation for 
3.7.1 and should be I think.

 From the commit there is this:

     Implemented non-linear colour and pigment map interpolation.

     The syntax is changed as follows:

         COLOR_MAP:
           color_map { COLOR_MAP_BODY } | colour_map { COLOR_MAP_BODY }
         COLOR_MAP_BODY:
           COLOR_MAP_IDENTIFIER | [blend_mode INT] [blend_gamma FLOAT] 
COLOR_MAP_ENTRY...

         PIGMENT_MAP:
           pigment_map { PIGMENT_MAP_BODY }
         PIGMENT_MAP_BODY:
           PIGMENT_MAP_IDENTIFIER | [blend_mode INT] [blend_gamma FLOAT] 
PIGMENT_MAP_ENTRY...

     The possible values for blend_mode are as follows:

         0 (default): Colour interpolation is performed working gamma 
space as defined by assumed_gamma.
         1: Colour interpolation is performed in linear colour space.
         2: Colour interpolation is performed in the gamma space defined 
by blend_gamma (defaulting to 2.5).
         3: Chromaticity interpolation is performed in linear space, 
while brightness interpolation is performed in the gamma space defined 
by blend_gamma.

Sorry about the wrapping.

Bill P.


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From: Jim Holsenback
Subject: Re: Documentation for blend_mode and blend_gamma?
Date: 19 Nov 2016 14:45:24
Message: <58306584$1@news.povray.org>
On 11/18/2016 3:43 PM, William F Pokorny wrote:
> Christoph mentioned blend_mode elsewhere today. To my knowledge the two
> options blend_mode and blend_gamma are not yet in our documentation for
> 3.7.1 and should be I think.

http://wiki.povray.org/content/Documentation:Tutorial_Section_1#Version_3.7.1

btw: thanks for pulling the necessary info into your previous post ... 
made the task /much/ easier :-)


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From: William F Pokorny
Subject: Re: Documentation for blend_mode and blend_gamma?
Date: 19 Nov 2016 19:45:37
Message: <5830abe1$1@news.povray.org>
On 11/19/2016 09:45 AM, Jim Holsenback wrote:
> On 11/18/2016 3:43 PM, William F Pokorny wrote:
>> Christoph mentioned blend_mode elsewhere today. To my knowledge the two
>> options blend_mode and blend_gamma are not yet in our documentation for
>> 3.7.1 and should be I think.
>
> http://wiki.povray.org/content/Documentation:Tutorial_Section_1#Version_3.7.1
>
>
> btw: thanks for pulling the necessary info into your previous post ...
> made the task /much/ easier :-)
>
Thanks Jim, Looks good.

As I looked over these updates I did notice we still have statements 
for the *_maps sections like:

"There may be from 2 to 256 entries in the map."

I believe Christoph eliminated that limit in the 3.7.1 master. Commit 
cf1c3fb :

     Refactored blend map handling
     Removed the hard-coded limit of 256 blend map entries along the way.
...

Bill P.


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