[Bf-committers] A contribution

[Dan Brown]

I can only find reference to 2 common file formats used solely for depth buffers.

.zpic - Output by softImage from what I can tell and importable into 
AfterEffects, Combustion, and Photoshop. This is just a headerless file of 
floats, 1 per pixel. I didn't find any more info than that such as the range 
used and orientation but I will keep looking.

.eiz - Output by ElectricImage and importable into the same apps as above with 
plugins. I couldn't find any info at all on the file format for this except that 
it can support multiple images for animations.

The Maya (.iff) and 3ds max (.rla superceded by .rpf) formats save the depth 
internally along with image and alpha data.

That is all from Google, so it may not be 100% correct.

I haven't got access to any of these apps though, so I can't try and work out 
exactly how they work. I did fid plugins for photoshop and viewers that I can 
use though if anyone does have one of these files lying around.

I will carry on looking for any specifications for both of them.

For integrating into Blender, I now think that a toggleable 'save zbuf' button 
in the Render panel would be better than adding it as a new image file format 
that just saves the depth component. Mainly because if you render an animation 
that takes several minutes/hours, you will only need to render it once that way.

Dan

Ton Roosendaal wrote:
> Hi,
> 
> While rendering with Blender, only the zbuffer values of  
> non-transparent objects are stored. Also halos don't get into the  
> zbuffer. The unified render even doesn't store a zbuffer at all.
> 
> Further, the internal storage is with unsigned int. Converting that to  
> a floating point value will only lower the resolution.
> 
> So, it's not about the best method to export, it just depends on the  
> program that accepts zbuffer images as input. To be added to a Blender  
> release, we therefore best choose the format as Gimp or Photoshop or  
> another compositing package accepts. So what's common here?
> 
> BTW: The IriZ format is an own invention used in NeoGeo days, to allow  
> usage in sequence effects. Afaik no other program uses it.
> 
> -Ton-
> 
> 
> On Wednesday, Jun 30, 2004, at 20:53 Europe/Amsterdam, Dan Brown wrote:
> 
>> TIFF is just a container format, much like a .zip file but not  
>> neccesarily compressed. It has an internal directory pointing to  
>> 'files' inside the tiff, and one of these can be a array of 32-bit or  
>> 64-bit floats if it is required. But it is up to the viewing  
>> application as to what it does with those 'files' and I couldn't find  
>> any mention of any common software using floats or even 32-bit per  
>> component integers for images, only high-end apps like Combustion. If  
>> we can find specs for a float image file format inside a tiff then it  
>> is an option, otherwise it would be proprietry to Blender as we would  
>> need to know where it stores things like width and height of that  
>> buffer before other peoples software could use it.
>>
>> There is no reason why a tiff handler couldn't be added to save the  
>> depth buffer as well/instead of a seperate raw file, like the  
>> Iris-zbuf format does now, then people have the option to use a  
>> straight float/32-bit int file or include it in the tiff.
>>
>> Dan
>>
>> Jonathan Merritt wrote:
>>
>>> How about adding support for TIFF images to Blender?  Am I wrong in  
>>> thinking that TIFF can support color, alpha and depth channels (and  
>>> others...) simultaneously?  AFAIK, TIFF supports 32- and 64-bit IEEE  
>>> floating point pixel formats too!
>>> It just seems a little odd to cobble an extra channel on to an  
>>> existing image format in a non-standard way like this.
>>>
>>>> Campbell Barton wrote:
>>>>
>>>>> I think a 16 bit greyscale PNG would be the go-
>>>>> Blender can load 16 bt png's (tho only as 8 bits for displaying) 
>>>>> so  it wouldent be odd.
>>>>> (Blender would be able to read the file it outputted)
>>>>> - Cam
>>>>
>>>>
>>>>
>>
>> _______________________________________________
>> Bf-committers mailing list
>> Bf-committers@blender.org
>> http://www.blender.org/mailman/listinfo/bf-committers
>>
>>
> ------------------------------------------------------------------------ --
> Ton Roosendaal  Blender Foundation ton@blender.org  http://www.blender.org
> 
> _______________________________________________
> Bf-committers mailing list
> Bf-committers@blender.org
> http://www.blender.org/mailman/listinfo/bf-committers
> 
> 
>