POV-Ray : Newsgroups : povray.general : Translating old image_maps : Re: Translating old image_maps Server Time
11 Aug 2024 13:13:52 EDT (-0400)
  Re: Translating old image_maps  
From: Bob Hughes
Date: 13 Jul 1999 00:52:30
Message: <378AC5F3.1AB4586E@aol.com>
Did you also try it with commas in the vector? Been awhile since I even
used a vector in the 'plane' statement.


PoD wrote:
> 
> Ken wrote:
> >
> > PoD wrote:
> > >
> > > I have an old POV file which has image_maps declared in the following
> > > manner
> > >
> > > image_map {
> > >   <0 1 -1>
> > >   tga "blah.tga"
> > >   ...}
> > >
> > > The warnings I get suggest that the vector at the top is for orienting
> > > the image, but it's ignored in 3.1.
> > > I don't have docs for old enough versions to explain this vector, how do
> > > I transform this image_map to get the same effect?
> > >
> > > Thanks, PoD.
> >
> > Here is what I could find for you from the Pov v1.0 docs:
> >
> >        The documentation for image_map explains the basic options
> >        which are true for all mapping types.
> >
> >        image_map - Color Pattern.
> >        Syntax:
> >        image_map { [map_type #] [<gradient>] image_type "filename"
> >        [alpha # #] [once] [interpolate #] }
> >
> >        This is a special color pattern that allows you to import a
> >        bitmapped image file in GIF, TGA, IFF, or DUMP format and
> >        map that bitmap onto an object.
> >
> >        For example:
> >
> >        // Use planar (type 0) mapping to project falwell.gif
> >        // onto the shape in a repeating pattern.
> >        // Set interpolation to 2 (bilinear) so the mapped GIF will
> >
> >        // be smoothed and not look jaggy.
> >        image_map {
> >          map_type 0 <1 0 -1> gif "falwell.gif" interpolate 2
> >        }
> >
> >        or
> >
> >        // Use spherical (type 1) mapping to
> >        // wrap earth.tga once onto a unit sphere
> >        // No interpolation is used, so it may look
> >        // jaggy
> >        image_map {
> >          map_type 1 tga "earth.tga"
> >        }
> >        or
> >        // Use cylindrical (type 2) mapping to wrap
> >        // cambells.gif once onto a unit cylinder.
> >        // Set interpolation to 4 (normalized distance)
> >        // so the mapped GIF will be smoothed and not look jaggy.
> >        //  Norm dist isn't as good as bi-linear, but it's faster.
> >        image_map {
> >          map_type 2 <1 -1 0> gif "cambells.gif" interpolate 4
> >        }
> >
> >        The texture in the first example will be mapped onto the
> >        object as a repeating pattern. The once keyword places only
> >        one image onto the object instead of an infinitely repeating
> >        tiled pattern. When once is used, the color outside the
> >        mapped texture is set to transparent. You can use the
> >        layered textures to place other textures or colors below the
> >        image.
> >
> >        The image map methods sphere, cylinder, and torus, wrap the
> >        image once and only once around a unit shape of the same name. The
> >        map may be scaled uniformly to apply to larger shapes. The maps
> >        may be applied to any shapes, but the results are undefined.
> >
> >        The planar image map method is like a slide projector and
> >        will work the same for any shape.
> >
> > --
> > Ken Tyler
> >
> > mailto://tylereng@pacbell.net
> 
> Thanks Ken,
>   I could of course use the #version directive, and would on a large
> file but I'm just the sort of person who likes to know how things
> actually work.
> 
> Cheers, PoD.

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