POV-Ray : Newsgroups : povray.general : Problems with textures and alpha channels... Server Time
5 Nov 2024 08:04:30 EST (-0500)
  Problems with textures and alpha channels... (Message 1 to 8 of 8)  
From: Shark
Subject: Problems with textures and alpha channels...
Date: 13 Nov 2005 13:45:00
Message: <web.437789047eadb4107ed350230@news.povray.org>
Hi,

I'm trying to get the gold textures in "golds.inc" to work when I have alpha
set to on in the INI file. Unfortunately, the textures end up appearing
really dull in the output. I was wondering if ayone could help.
Shark


Post a reply to this message

From: Warp
Subject: Re: Problems with textures and alpha channels...
Date: 13 Nov 2005 17:16:06
Message: <4377bb25@news.povray.org>
Shark <nomail@nomail> wrote:
> I'm trying to get the gold textures in "golds.inc" to work when I have alpha
> set to on in the INI file. Unfortunately, the textures end up appearing
> really dull in the output. I was wondering if ayone could help.

  Are you sure this is related to the alpha channel usage?

  Do they not look dull when you don't use alpha channel?

  If they still look dull even when you turn alpha channel off, then the
problem is elsewhere.

-- 
                                                          - Warp


Post a reply to this message

From: Alain
Subject: Re: Problems with textures and alpha channels...
Date: 13 Nov 2005 17:30:17
Message: <4377be79$1@news.povray.org>
Shark nous apporta ses lumieres en ce 2005-11-13 13:43:
> Hi,
> 
> I'm trying to get the gold textures in "golds.inc" to work when I have alpha
> set to on in the INI file. Unfortunately, the textures end up appearing
> really dull in the output. I was wondering if ayone could help.
> Shark
> 
> 
> 
Have you tried to remove the ambient from those textures? I think that they looks
better that way. 
Try using another colour for the background. It get replaced by transparent but still
show in 
reflections.

-- 
Alain
-------------------------------------------------
AAAAAA: American Association Against Acronym Abuse and Ambiguity.


Post a reply to this message

From: Zeger Knaepen
Subject: Re: Problems with textures and alpha channels...
Date: 13 Nov 2005 18:20:06
Message: <4377ca26@news.povray.org>
"Warp" <war### [at] tagpovrayorg> wrote in message 
news:4377bb25@news.povray.org...
> Shark <nomail@nomail> wrote:
> > I'm trying to get the gold textures in "golds.inc" to work when I 
have alpha
> > set to on in the INI file. Unfortunately, the textures end up 
appearing
> > really dull in the output. I was wondering if ayone could help.
> 
>   Are you sure this is related to the alpha channel usage?
> 
>   Do they not look dull when you don't use alpha channel?
> 
>   If they still look dull even when you turn alpha channel off, then 
the
> problem is elsewhere.

this sounds like a bug I noticed a while ago: with using alpha-channel 
the color-clipping seems to be done entirely differently.  However, this 
bug seems to be solved in POV-Ray 3.6.1

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com


Post a reply to this message

From: Marc Jacquier
Subject: Re: Problems with textures and alpha channels...
Date: 14 Nov 2005 03:15:45
Message: <437847b1@news.povray.org>

news:web.437789047eadb4107ed350230@news.povray.org...
> Hi,
>
Hi
Mayby it is the lack of environnement.
A reflecting texture is only reflecting if it has something to reflect. (QOD
;-)

Marc


Post a reply to this message

From: Zeger Knaepen
Subject: Re: Problems with textures and alpha channels...
Date: 14 Nov 2005 06:57:12
Message: <43787b98$1@news.povray.org>
> this sounds like a bug I noticed a while ago: with using alpha-channel 
the color-clipping seems to be done entirely differently.  However, 
> this bug seems to be solved in POV-Ray 3.6.1

on second thought... the mosaic-preview looks ok, but the final render 
doesn't :(

example-scene:

    camera {location -z look_at 0}
    light_source {<500,500,-500> rgb 1}
    sphere {0,.2 pigment {red 1} finish {specular 1 diffuse 1}}


ini-settings:

    +sp8 +ep4 +ua


Tested in MegaPOV 1.1 and POV-Ray 3.6.1, under Windows XP SP1, Athlon XP 
2500+ 1GB RAM


cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com


Post a reply to this message

From: Shark
Subject: Re: Problems with textures and alpha channels...
Date: 14 Nov 2005 15:20:01
Message: <web.4378f0ed81eeb59294338110@news.povray.org>
Maybe I will try rendering at twice the normal image size, then use mosaic
preview until it's at the desired 'resolution', and finally resize the
output by 1/2.

"Zeger Knaepen" <zeg### [at] povplacecom> wrote:
> on second thought... the mosaic-preview looks ok, but the final render
> doesn't :(


Post a reply to this message

From: Zeger Knaepen
Subject: Re: Problems with textures and alpha channels...
Date: 14 Nov 2005 18:20:20
Message: <43791bb4$1@news.povray.org>
"Shark" <nomail@nomail> wrote in message 
news:web.4378f0ed81eeb59294338110@news.povray.org...
> Maybe I will try rendering at twice the normal image size, then use 
mosaic
> preview until it's at the desired 'resolution', and finally resize the
> output by 1/2.

POV-Ray doesn't save the mosaic preview, and there's no AA, so that's 
not really a good approach, I'm afraid :(

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.