Hi,

I want to put a structure from a GIF file on another texture.
So I defined the ground-texture and the texture with the image map and
created a new texture like this :
my_texture =
texture { t_ground }
texture { t_image } // Color 0 was set to a transparency of 100%.

and applied it to my object.
But instead of showing the ground-texture where the image shows color 0
I only see a black area.
If I set the once-attribute in the image_map I see the ground-texture
around the image but still have the black areas in the image.

What am I doing wrong ?

Thanks for any help,
Hendrik Iben

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Hendrik

Could you post the actual texture statements from your pov
source, so that we can get a better idea of what might be
wrong. 



-- 
Cheers
Steve              email mailto:sjl### [at] ndirectcouk

%HAV-A-NICEDAY Error not enough coffee  0 pps. 

web http://www.ndirect.co.uk/~sjlen/

or  http://start.at/zero-pps

  3:43am  up 23:35,  5 users,  load average: 1.00, 1.00, 1.04

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You can't get a transparent palette entry which is set in a image program to
show up as transparent in POV-Ray unless you use the 'transmit' keyword.  Such
as:

#declare t_image=texture{pigment{
 image_map {gif "yourimage.gif" transmit 0,1} // index #0, transmit 1
 }}

 my_texture =
 texture { t_ground }
 texture { t_image }

The once keyword is only for non-tiling.  Be certain of your palette index
number/color relation too.  Black might not always be 0.

Bob

"Hendrik Iben" <Hen### [at] bigfootde> wrote in message
news:38B84DD4.E5340CA8@bigfoot.de...
| Hi,
|
| I want to put a structure from a GIF file on another texture.
| So I defined the ground-texture and the texture with the image map and
| created a new texture like this :
| my_texture =
| texture { t_ground }
| texture { t_image } // Color 0 was set to a transparency of 100%.
|
| and applied it to my object.
| But instead of showing the ground-texture where the image shows color 0
| I only see a black area.
| If I set the once-attribute in the image_map I see the ground-texture
| around the image but still have the black areas in the image.
|
| What am I doing wrong ?
|
| Thanks for any help,
| Hendrik Iben
|

Post a reply to this message

Okay,
This is the actual non working layered texture from my scene.
It's applied to exacly the same plane I used here.
Color 0 in the image is Red as this was easier for me to view the
transparent areas.

#declare image_texture =
texture {
        pigment {
                image_map
                        {
                        gif "image.gif"
                        once
                        transmit 0,1.0
                        }
                }
        }

#declare plane_texture =
texture {
T_Stone17
rotate <90,0,0>
scale 4
}
texture {
image_texture
rotate <90,0,0>
translate <-.5,0,1.5>
scale 4
}

plane {
y*1,0
texture { plane_texture }
}

I hope it gets clearer now,
Hendrik Iben

Steve wrote:

> Hendrik
>
> Could you post the actual texture statements from your pov
> source, so that we can get a better idea of what might be
> wrong.
>
> --
> Cheers
> Steve              email mailto:sjl### [at] ndirectcouk
>
> %HAV-A-NICEDAY Error not enough coffee  0 pps.
>
> web http://www.ndirect.co.uk/~sjlen/
>
> or  http://start.at/zero-pps
>
>   3:43am  up 23:35,  5 users,  load average: 1.00, 1.00, 1.04

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I tried it exactly the way you described (Color 0 is Red in my image, and I am
sure 0 is the index I want.).
Please view the following post to 'Re: Q: Image-Maps in Layered Textures' by Steve
for the original code that does not work.

Thanks,
Hendrik Iben

Bob Hughes wrote:

> You can't get a transparent palette entry which is set in a image program to
> show up as transparent in POV-Ray unless you use the 'transmit' keyword.  Such
> as:
>
> #declare t_image=texture{pigment{
>  image_map {gif "yourimage.gif" transmit 0,1} // index #0, transmit 1
>  }}
>
>  my_texture =
>  texture { t_ground }
>  texture { t_image }
>
> The once keyword is only for non-tiling.  Be certain of your palette index
> number/color relation too.  Black might not always be 0.
>
> Bob

Post a reply to this message

I think you may have found a bug.  'transmit' doesn't work right but 'filter'
does okay.

Bob

Post a reply to this message

Btw, I tried this with version 3.02.watcom.win32, 3.1g.watcom.win32, and also
MegaPov 0.4.  Only MegaPov will render correctly when 'transmit' is used,
'filter' works okay in all 3 versions.  I thought maybe it might be
'max_trace_level' dependant but it doesn't help if it's increased to 50 instead
of leaving at default 5.  So something got fixed in Nathan's patched pov.

Bob

"Bob Hughes" <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
news:38b93247@news.povray.org...
| I think you may have found a bug.  'transmit' doesn't work right but 'filter'
| does okay.
|
| Bob
|
|
|

Post a reply to this message

Yes, I found out the same thing just before I read this post... :-)
I didn't try filter in the beginning because I thought this would let only the
red component of the ground through,
as Color 0 is Red...
I don't think it is a bug because when I took a very close look I could see the
texture below in the dark... it seems to be scaled down in color or something,
but in the end it's just too dark...

I had the same effect when I just used a simple checker :
texture {
pigment {
checker color rgbt <0,0,1,0>, color rgbt <1,1,1,1>
}
}

But filter works and I'm happy again :-)

Thanks,
Hendrik Iben

Bob Hughes wrote:

> I think you may have found a bug.  'transmit' doesn't work right but 'filter'
> does okay.
>
> Bob

Post a reply to this message

Well, I guess I should get that patch if I want to make more scenes like the one
I'm creating now...

But this problem did at least restore my faith in myself and my abilities so this
experience was not that bad at all...
;-)

Thanks again for the information,
Hendrik Iben

Bob Hughes wrote:

> Btw, I tried this with version 3.02.watcom.win32, 3.1g.watcom.win32, and also
> MegaPov 0.4.  Only MegaPov will render correctly when 'transmit' is used,
> 'filter' works okay in all 3 versions.  I thought maybe it might be
> 'max_trace_level' dependant but it doesn't help if it's increased to 50 instead
> of leaving at default 5.  So something got fixed in Nathan's patched pov.
>
> Bob

Post a reply to this message

Yep, I just realized it was actually there too, not blacked out and gone
entirely, just very dark.  I turned up the color of the light source to 10.
Something's wrong in the official versions though, I just couldn't say not
knowing anything about the source code workings.  Maybe Nathan has an idea.
At the beginning I simply thought the problem might be the layering over a
layered texture, which I expected would make an error show up.  Maybe that's
still something to do with it though.

Bob

"Hendrik Iben" <Hen### [at] bigfootde> wrote in message
news:38B93739.57A3562E@bigfoot.de...
| Yes, I found out the same thing just before I read this post... :-)
| I didn't try filter in the beginning because I thought this would let only the
| red component of the ground through,
| as Color 0 is Red...
| I don't think it is a bug because when I took a very close look I could see
the
| texture below in the dark... it seems to be scaled down in color or something,
| but in the end it's just too dark...
|
| I had the same effect when I just used a simple checker :
| texture {
| pigment {
| checker color rgbt <0,0,1,0>, color rgbt <1,1,1,1>
| }
| }
|
| But filter works and I'm happy again :-)
|
| Thanks,
| Hendrik Iben
|
| Bob Hughes wrote:
|
| > I think you may have found a bug.  'transmit' doesn't work right but
'filter'
| > does okay.
| >
| > Bob
|

Post a reply to this message