POV-Ray : Newsgroups : povray.bugreports : uv_mapping bug on cylinders : uv_mapping bug on cylinders Server Time
8 Aug 2022 20:59:25 EDT (-0400)
  uv_mapping bug on cylinders  
From: Chris R
Date: 3 Aug 2022 10:40:00
Message: <web.62ea88024cd911261ec2018a5cc1b6e@news.povray.org>
I encountered an issue with v3.8 beta 2 using uv_mapping textures on cylinders
while creating a label for a bottle.  I did search through the newsgroups for
any other report of this and didn't find anything that matches my problem.

The original texture is fairly complex and involves using an object pattern with
a text object as the "object" and fully-specified textures for the ink and the
background of the label as the texture list.  However, I was able to simplify it
considerably to the following:

            cylinder {
                <0, 0, 0>,
                <0, 20, 0>,
                5
                texture { uv_mapping pigment { brick color rgb 0 color rgb 1 } }
            }
            cylinder {
                <0, 0, 0>,
                <0, 20, 0>,
                5
                texture { uv_mapping pigment { brick color rgb 0 color rgb 1 } }
                translate <20, 0, 0>
            }

As you can see, the second cylinder is translated after applying the texture,
but if you look at the brick pattern, it appears the uv_mapping is being applied
to the translated object first, because the bricks do not line up.

In my bottle example, the text doesn't show up at all in the translated bottle,
because the entire bottle is outside of the text object's boundaries after it is
translated.

-- Chris R.


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