Hi. I've been using this code in a color map. In 3.6 it behaves as expected. In
3.7RC4,  all my colors are shifted to cyan, magenta, yellow, and white.  This
makes me wonder if the mod() function is behaving differently in 3.7RC4, or if
it requires a different syntax now.  Crazy hypothesis, but so are the results
compared to 3.6.



For any two vectors of length <1, I use:

rgb< mod(a.x+b.x,1),mod(a.y+b.y,1),mod(a.z+b.z,1)>

Post a reply to this message

Am 02.03.2012 03:28, schrieb gregjohn:
> Hi. I've been using this code in a color map. In 3.6 it behaves as expected. In
> 3.7RC4,  all my colors are shifted to cyan, magenta, yellow, and white.  This
> makes me wonder if the mod() function is behaving differently in 3.7RC4, or if
> it requires a different syntax now.  Crazy hypothesis, but so are the results
> compared to 3.6.

The mod() function hasn't been touched since ages. But gamma handling 
has, and can cause exactly the effect you see.

> rgb<  mod(a.x+b.x,1),mod(a.y+b.y,1),mod(a.z+b.z,1)>

Instead, try this:

   srgb <mod(a.x+b.x,1),mod(a.y+b.y,1),mod(a.z+b.z,1)>

Or, if you're using this recursively, leave that line unchanged, and 
instead set the initial values of a and b like this:

   #declare a = srgb<...>;
   #declare b = srgb<...>;


Alternatively (though not recommended if you're aiming for realism) you 
can specify "global_settings { assumed_gamma srgb }".

Post a reply to this message