Ken wrote:
> 
> I don't get it !
> 
> 1.) image_pattern ?
> 
>   There is a new pattern type included with the Photon Patch of Pov-Ray
> called "image_pattern". What is the purpose of this addition. I looked
> at the example given at Nathan's patch site and read the description
> but I am not following the reason for it's existence and when it is
> appropriate to use it. I had no problem recreating the example image
> shown at the site with existing texture and pigment procedures.

This was made for Thomas Baier for use with 3DS to POV conversions.  Let's
say you have two textures, and you want to use a black and white image
to fade between the two textures.  Now lets say all you have to work with
is material_map.  That would be a lot of work.  If you only wanted to use
two textures (no fading between), that would be easy, but since material_map
uses indices and single textures, fading would be very difficult and you'd
have a lot of "average{ texture_map { [0.5 t1] [0.4 t2] }}" statements.
You could put it in a while loop, but that would still be a lot of extra
work.

Now, on the other hand, if you have image_pattern, you can use texture_map
instead of material_map, and just use the image as your image_pattern.
Simple.  Fast.  Saves memory (no need for 256 textures for those 256
shades of grey).

-Nathan

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