[Bf-vfx] Blender camera tracking approach

[Tobias Kummer]

Hey Remo!

Well, some kind of barrel distortion is natural with (almost) every 
lens. Also, when e.g. wide angle lenses are used, the look of it is on 
purpose - I wouldn't want to have straight parallel lines in the result, 
but keep the distortion (extreme example: fish-eye lens).
Regarding your other email - I agree. Format support is crucial here, 
otherwise the needed conversion is bad quality-wise. The transcoding at 
the post-compositing saving stage is needed in every other package too 
though.

Greets, Tobi


On 05/08/2011 08:06 PM, Remo Pini wrote:
> I kind of disagree...
>
> If you have lens distortion in you footage, this would most likely be
> bad and you would not want the final result to have that in it anymore,
> sooo....
>
> (1) shoot
> (2) remove lens distortion
> (3) track
> (4) add 3d stuff
> (5) composite
>
> I'm having a hard time to think of a situation where you would WANT to
> have lens distortion in your final product...
>
> Cheers
>
> Remo
>
>> -----Original Message-----
>> From: bf-vfx-bounces at blender.org [mailto:bf-vfx-bounces at blender.org]
>> On Behalf Of Tobias Kummer
>> Sent: Sonntag, 8. Mai 2011 3:49
>> To: bf-vfx at blender.org
>> Subject: [Bf-vfx] Blender camera tracking approach
>>
>> Hey all!
>>
>> Here are some of my thoughts on the matchmoving workflow in blender,
>> after some discussion in IRC chat. Since I've never used Pfmatchit, I
>> cannot say anything about it, but when Syntheyes was mentioned I
> looked
>> into it a little and thought its workflow might be suboptimal.
>> It re-applies lens distortion on an image post-processing level, which
>> is bad quality-wise. A better way would be setting blenders camera
>> parameters, so the rendered output already has matching distortion and
>> does not have to be altered afterwards (which brings up the topic
>> blender real world camera settings - would be desirable anyway).
>> See this (crappy) flowchart as illustration:
>> http://www.pasteall.org/pic/12079
>>
>> The first step in the proposed workflow accomodates for the fact that
>> blender cannot draw lens distortions in the 3D viewport. So the
>> outcoming undistorted footage is just used for visualisation purposes
>> for the artist - for rendering/compositing, the original distorted
>> footage would be used. This way, we skip the step that compromises
> quality.
>> As blender will have combined 3D/tracking functionality, we should
>> leverage on that and not copy the tracking-only workflow of other
> packages.
>> Please correct me if there are any major mistakes in my thoughts!
>>
>> Greets,
>>
>> Tobias
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