Hi,

I'm trying to figure out if it is possible with povray to get the 
following additional information for each pixel as a separate text or 
image file:
- x,y,z coordinates pixel
- Normal vector
- texture (before application of lightning, etc.)

I have not found a description of something similar in the documentation, 
but maybe there are some hidden debug options which can be activated?

Best regards,
                Matthias

Post a reply to this message

Am 28.10.2011 18:56, schrieb Matthias Wieser:
> Hi,
>
> I'm trying to figure out if it is possible with povray to get the
> following additional information for each pixel as a separate text or
> image file:
> - x,y,z coordinates pixel

I guess you mean the 3D coordinates of the (nearest) object hit.

There are two possible ways of obtaining this information; both will 
require you to run the render a second time:

- Use special textures that give you access to the desired information. 
A texture with averaged red, green and blue gradients and an 
ambient-only (POV-Ray 3.7: emission-only) finish should do.

- Use MegaPOV, which gives you access to this information with its 
post-processing features.

Make sure to use a sufficient bit depth for the output image - I suggest 
16 bit per color channel, using e.g. PNG - and set the file gamma to 
linear (assumed_gamma 1.0, and File_Gamma=1.0 for POV-Ray 3.7 or 
Display_Gamma=1.0 for POV-Ray 3.6 / MegaPOV) for this stunt.

> - Normal vector

Ditto, except that the special texture would be an average of three 
slope patterns.

> - texture (before application of lightning, etc.)

For this you will need to use the special-textures approach, as 
MegaPOV's post-processing does not help with this. Use the same textures 
as for the normal scene, but set the finish to ambient- or 
emission-only. Depending on how you want transparency to be handled, you 
might also need to change any filter or transmit components in the 
pigment as well.

> I have not found a description of something similar in the documentation,
> but maybe there are some hidden debug options which can be activated?

No hidden debug options, sorry.

Post a reply to this message

clipka wrote:

> Am 28.10.2011 18:56, schrieb Matthias Wieser:
>> Hi,
>>
>> I'm trying to figure out if it is possible with povray to get the
>> following additional information for each pixel as a separate text or
>> image file:
>> - x,y,z coordinates pixel
> 
> I guess you mean the 3D coordinates of the (nearest) object hit.

Yes, that's right.

> There are two possible ways of obtaining this information; both will
> require you to run the render a second time:
> 
> - Use special textures that give you access to the desired information.
> A texture with averaged red, green and blue gradients and an
> ambient-only (POV-Ray 3.7: emission-only) finish should do.
> 
> - Use MegaPOV, which gives you access to this information with its
> post-processing features.
> 
> Make sure to use a sufficient bit depth for the output image - I
> suggest 16 bit per color channel, using e.g. PNG - and set the file
> gamma to linear (assumed_gamma 1.0, and File_Gamma=1.0 for POV-Ray 3.7
> or Display_Gamma=1.0 for POV-Ray 3.6 / MegaPOV) for this stunt.

Thank you, I will try.

Matthias

Post a reply to this message