Hello people.

I understand 3.7beta > 10 has now gamma-enabled by default, at 2.2 if I
understand correctly.

I have this scenario: A simple box, with an image_map projected from a
PNG image (which, I understand, defines it's proper gamma). I declared a
finish (ambient 1), and I don't use any light source (I wanted to have a
garanteed uniform lighting).

The rendered image is way too light. I can only return to normal results
if I disable gamma, by defining assumed_gamma 2.2). 

What am I doing wrong here? Shouldn't the process be transparent in this
case?

John.

(This is 3.7beta34, compiled on linux)

Post a reply to this message

John Coppens <joh### [at] johncoppenscom> wrote:
> I have this scenario: A simple box, with an image_map projected from a
> PNG image (which, I understand, defines it's proper gamma). I declared a
> finish (ambient 1), and I don't use any light source (I wanted to have a
> garanteed uniform lighting).

> The rendered image is way too light.

  You have to specify the assumed gamma for the image used in the image_map.

  This feature has not yet been implemented. It will be implemented in a
future beta. (It may even be possible to specify a default assumed gamma
for all input images.)

-- 
                                                          - Warp

Post a reply to this message

> John Coppens <joh### [at] johncoppenscom> wrote:
>> I have this scenario: A simple box, with an image_map projected from a
>> PNG image (which, I understand, defines it's proper gamma). I declared a
>> finish (ambient 1), and I don't use any light source (I wanted to have a
>> garanteed uniform lighting).
> 
>> The rendered image is way too light.
> 
>   You have to specify the assumed gamma for the image used in the image_map.
> 
>   This feature has not yet been implemented. It will be implemented in a
> future beta. (It may even be possible to specify a default assumed gamma
> for all input images.)
> 

Speaking of future beta, the current one has expired 7 weeks ago. Is 
there any estimate for beta 35 release?



Alain

Post a reply to this message

On 23 Nov 2009 11:34:20 -0500
Warp <war### [at] tagpovrayorg> wrote:

>   You have to specify the assumed gamma for the image used in the
> image_map.

Just asking - isn't the gamma for PNG images defined in the image?

>   This feature has not yet been implemented. It will be implemented in a
> future beta.

Ok, so I'm suspecting to be correct in disabling gamma correction then -
as the image is the only object I'm interested in (at the moment) is the
image_map, I have now a 1:1 from input to output.

Thanks!

John

Post a reply to this message

John Coppens <joh### [at] johncoppenscom> wrote:
> On 23 Nov 2009 11:34:20 -0500
> Warp <war### [at] tagpovrayorg> wrote:

> >   You have to specify the assumed gamma for the image used in the
> > image_map.

> Just asking - isn't the gamma for PNG images defined in the image?

  POV-Ray 3.7 is not yet taking into account the input PNG gamma info
properly, IIRC.

> >   This feature has not yet been implemented. It will be implemented in a
> > future beta.

> Ok, so I'm suspecting to be correct in disabling gamma correction then -
> as the image is the only object I'm interested in (at the moment) is the
> image_map, I have now a 1:1 from input to output.

  You could also use #version 3.6 to make it use the same settings as
POV-Ray 3.6. That will most probably work on the final version of 3.7
as well.

-- 
                                                          - Warp

Post a reply to this message