[Sidefx-houdini-list] Camera model

Neil Scholes neil at uvfilms.co.uk
Thu Nov 29 07:01:46 EST 2012


Yes absolutely

I manged to get the precompiled binaries working in Nuke - works a treat

I wouldn't know where to start using this info for building a Houdini 
lens shader!!

Anyone out there who can? - well id buy you at least 2 pints.

A COP node would be cool but not _as_ cool.


Neil Scholes

www.uvfilms.co.uk
+44 (0) 7977 456 197

On 29/11/12 11:48, Frederic Servant wrote:
> Hi,
>
> 3DE's Lens Distortion Plugin Kit (
> http://www.3dequalizer.com/index.php#?site=tech_docs&id=110216_01) is free
> to download and use.
>
> Science-D-Visions recently started to make available a lens database to
> feed it  http://www.3dequalizer.com/index.php#?site=tech_docs&id=120930_01,
> of course you can feed it your own 3DE distortion parameters.
>
> Besides Weta's Nuke plugin (
> https://github.com/wetadigital/lensDistortion_3de), some 3DE distortion
> lens shaders have been done for other renderers (mentalray:
> https://bitbucket.org/lamaison/lmwarpdistort/wiki/Home  and Arnold:
> http://s3aws.obliquefx.com/public/shaders/Obq_UVRemapLensDistortion_v204.html
> ).
>
> With all those examples, it should be easy enough to do a distort/undistort
> cop node or a lens shader for mantra.
> --
> Fred
>
>
> On Thu, Nov 29, 2012 at 10:29 AM, Neil Scholes <neil at uvfilms.co.uk> wrote:
>
>> Yeah I like
>>
>> in nuke you can use a plugin to match the lens distortion generated by
>> 3DEqualiser - which is great because it has an excellent series of ways to
>> model the lens of a whole range of different cameras - far better than
>> Nukes own lens distortion node
>>
>> Specifically the Anamorphic Model - it rocks and is really complex
>>
>> I don't have the tech to build into Houdini - but there must be a way  -
>> importing lens models from all the different 3D trackers out there, and
>> applying before you render.
>>
>> Obviously you may not want to do this on a project - but i'd love to.
>>
>>
>>
>>
>> Neil Scholes
>>
>> www.uvfilms.co.uk
>> +44 (0) 7977 456 197
>>
>> On 29/11/12 09:02, Javier Meroño wrote:
>>
>>> what about a solution like this but for real?
>>>
>>> http://www.itsartmag.com/**reviews/Lightwave9/**realcameralens.jpg<http://www.itsartmag.com/reviews/Lightwave9/realcameralens.jpg>
>>>
>>> with "for real", I mean that Lightwave (yup, that´s a Lightwave screen
>>> grab) lens only takes into account lens distortion and fakes the amount of
>>> light entering the lens with a "pin" lens effect but it´s not really
>>> changing it based on ISO or lens shutter. It wouldn´t make much sense since
>>> Lightwave´s renderer ain´t physically based right now.
>>> This being said, the amount of different camera lenses modelled into
>>> their camera shader is staggering. It´s useful if only for the lens
>>> distortion.
>>>
>>> If we could have a similar panel with real camera behaviour we would be
>>> able to choose our "starting point".
>>>
>>> regards,
>>>
>>> Javier Meroño
>>>
>>>
>>>
>>>
>>>   From: jordibares at gmail.com
>>>> Date: Wed, 28 Nov 2012 17:59:43 +0000
>>>> To: sidefx-houdini-list at sidefx.com
>>>> Subject: Re: [Sidefx-houdini-list] Camera model
>>>>
>>>> Agreed, it is not that this particular approach is a silver bullet, just
>>>> trying to revisit every single part of the process.
>>>>
>>>> :-)
>>>>
>>>> jb
>>>>
>>>> On 28 Nov 2012, at 17:32, Pablo Giménez <pablogipi at gmail.com> wrote:
>>>>
>>>>   2012/11/28 Jordi Bares Dominguez <jordibares at gmail.com>
>>>>>   On 28 Nov 2012, at 11:35, Pablo Giménez <pablogipi at gmail.com> wrote:
>>>>>>   2012/11/28 Neil Scholes <neil at uvfilms.co.uk>
>>>>>>>   I would certainly love having a lens shader where you can import lens
>>>>>>>> distortion models from apps like 3DEqualiser etc.
>>>>>>>>
>>>>>>>> rather than having to render larger resolutions than needed and
>>>>>>>>
>>>>>>> distorting
>>>>>>> in nuke.
>>>>>>>>   Well, this is  debatable.
>>>>>>> If you "bake" the lens distortion in the render then you are forced to
>>>>>>> rerender in case for  soem reason this lens dostortion option changes
>>>>>>> in
>>>>>>> the future, or changes for some shots.
>>>>>>>
>>>>>> True, but the whole process is simplified as you don't need to deal
>>>>>> with
>>>>>> various sets of transformations on various points in the pipeline…
>>>>>> this may
>>>>>> be debatable, true, but I rather keep it simple and re-render when that
>>>>>> happens which is not that common in my experience.
>>>>>>
>>>>>>   And this happens sometimes.
>>>>>>> Whereas rendering some extra pixels is always a good thing,
>>>>>>>
>>>>>> I do not agree with that, I think that is a waste of rendering for
>>>>>> every
>>>>>> single pass of every single shot and you count the extra hours you
>>>>>> probably
>>>>>> would be horrified about it as I am.
>>>>>>
>>>>>>   Well, it depends on the scenario, for film, rendering 10% more pixels
>>>>> usually is not a big deal.
>>>>> But it is quite common to have shots that are really hard to render an
>>>>> due
>>>>> to changes in how it is going to be composited they needs to be rendered
>>>>> again and this cost more time/resources that rendering 10% more pixels
>>>>> in a
>>>>> bunch of shots.
>>>>> As always it depends on the scenario, being able to make the same thing
>>>>> in
>>>>> both render and comp is always good and welcome, so I don't have nothing
>>>>> against having a better camera model, just the opposite.
>>>>> Doing everything at the render stage is not always the best option, same
>>>>> thing goes about trying to "fake" as most as possible in comp.
>>>>> So a compromise between them depending on the situation is usually the
>>>>> best
>>>>> option.
>>>>>
>>>>>   just an
>>>>>>> overscan 1.1 will  allow you to add lens distortion in comp and also
>>>>>>> be
>>>>>>> sure that further comp manipulations like camera shakes will have
>>>>>>> enough
>>>>>>> pixels to work with.
>>>>>>>
>>>>>> I would rather have 3D camera shakes if possible… sometimes this may
>>>>>> not
>>>>>> be feasible for many reasons but...
>>>>>>
>>>>>> jb
>>>>>>
>>>>>>   I think it is better to render a bunch of extra pixels as a rule
>>>>>>> rather
>>>>>>> than be forced to rerender a expensive render.
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> Neil Scholes
>>>>>>>>
>>>>>>>> +44(0) 7977 456 197
>>>>>>>> www.uvfilms.co.uk
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On 28 Nov 2012, at 10:17, Jordi Bares Dominguez wrote:
>>>>>>>>
>>>>>>>>   The moment you enter into physically base rendering you will end up
>>>>>>>> wanting to use physically correct shaders and that ultimately will
>>>>>>>> take
>>>>>>>>
>>>>>>> you
>>>>>>> to realise that is actually not that useful unless you get it all
>>>>>>>> right
>>>>>>>> (physically correct camera and lights too) and also HDR balanced
>>>>>>>>
>>>>>>> properly
>>>>>>> (no grading)
>>>>>>>>> The cascade effect is huge and adapting to the approach is not easy
>>>>>>>>>
>>>>>>>> plus
>>>>>>> takes longer to render each frame but in my experience is more than
>>>>>>>> acceptable for the things you gain.
>>>>>>>>
>>>>>>>>> Ultimately, like apple did when they designed the iPad, one single
>>>>>>>>> rule
>>>>>>>>>
>>>>>>>> forced a ton of changes everywhere (no pen, just your finger), with
>>>>>>>> PBR
>>>>>>>>
>>>>>>> is
>>>>>>> the same and certain render engines are already there or thereabouts,
>>>>>>>> specially Maxwell, Vray and Mental Ray alongside all the other
>>>>>>>> flavours
>>>>>>>> inspired by these.
>>>>>>>>
>>>>>>>>> I really hope after this exchange of ideas SideFX see the value and
>>>>>>>>> put
>>>>>>>>>
>>>>>>>> together a physically correct ecosystem of tools for modern
>>>>>>>> rendering.
>>>>>>>>
>>>>>>>>> my 2 cents
>>>>>>>>> jb
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 28 Nov 2012, at 10:04, Neil Scholes <neil at uvfilms.co.uk> wrote:
>>>>>>>>>
>>>>>>>>>   Interesting thoughts
>>>>>>>>>> I was thinking that rendering linear light values in high dynamic
>>>>>>>>>>
>>>>>>>>> range
>>>>>>> is the real benefit  we already have, because after that all real
>>>>>>>> camera
>>>>>>>> limitations such as abberation grain and iso can be faked in a more
>>>>>>>> painterly way in the comp which is surely quicker and easier ?
>>>>>>>>
>>>>>>>>> Also the issues of real world lenses and ISO etc well each camera,
>>>>>>>>> lens
>>>>>>> is going to vary in accuracy even if the camera manufacturers offer a
>>>>>>>> template - rather like f stop vs T stop.
>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Neil Scholes
>>>>>>>>>>
>>>>>>>>>> +44(0) 7977 456 197
>>>>>>>>>> www.uvfilms.co.uk
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 28 Nov 2012, at 08:50, Jordi Bares wrote:
>>>>>>>>>>
>>>>>>>>>>   I would love that, including the camera transform matrix please.
>>>>>>>>>>> Jb
>>>>>>>>>>>
>>>>>>>>>>> Sent from my iPhone
>>>>>>>>>>>
>>>>>>>>>>> On 28 Nov 2012, at 00:32, Colin Doncaster <
>>>>>>>>>>> colin.doncaster at gmail.com
>>>>>>>>>>>
>>>>>>>>>> wrote:
>>>>>>>>>   Sure!  I would assume it would be helpful if all of the camera
>>>>>>>>>>> parameters ended up in metadata stored in the output image - this
>>>>>>>> fits
>>>>>>>>
>>>>>>> well
>>>>>>> into the EXR camera info as it's meant to represent what exposure the
>>>>>>> data
>>>>>>> represents with a good reference point from where to adjust it.
>>>>>>>>>   This would make a nice COP and/or MPlay addition where you can
>>>>>>>>>>> quickly adjust the values and round robin them back to the scene
>>>>>>>> camera.
>>>>>>>>
>>>>>>>>>   Cheers
>>>>>>>>>>>> On 2012-11-27, at 6:17 PM, Jordi Bares Dominguez <
>>>>>>>>>>>>
>>>>>>>>>>> jordibares at gmail.com> wrote:
>>>>>>>>>   I don't imagine anyone aspiring to get noise simulation baked in
>>>>>>>>>>>> their render and with the ever expanding electronic cameras
>>>>>>> configurations
>>>>>>> and codecs this simply may be impossible but it may be useful to get a
>>>>>>>> metric for density of noise in the picture that we can feed into the
>>>>>>>>
>>>>>>> comp.
>>>>>>>   hope it makes sense
>>>>>>>>>>>>> jb
>>>>>>>>>>>>>
>>>>>>>>>>>> ______________________________**_________________
>>>>>>>>>>>> Sidefx-houdini-list mailing list
>>>>>>>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>>>>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**
>>>>>>>>>>>> houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>>>>>>
>>>>>>>>>>> ______________________________**_________________
>>>>>>>>>>> Sidefx-houdini-list mailing list
>>>>>>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>>>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**
>>>>>>>>>>> houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>>>>>
>>>>>>>>>>>   ______________________________**_________________
>>>>>>>>>> Sidefx-houdini-list mailing list
>>>>>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**
>>>>>>>>>> houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>>>>
>>>>>>>>> ______________________________**_________________
>>>>>>>>> Sidefx-houdini-list mailing list
>>>>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**
>>>>>>>>> houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>>>
>>>>>>>>>   ______________________________**_________________
>>>>>>>> Sidefx-houdini-list mailing list
>>>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**
>>>>>>>> houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>>
>>>>>>>>
>>>>>>> --
>>>>>>> Un saludo
>>>>>>> Best Regards
>>>>>>> Pablo Giménez
>>>>>>> ______________________________**_________________
>>>>>>> Sidefx-houdini-list mailing list
>>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>
>>>>>> ______________________________**_________________
>>>>>> Sidefx-houdini-list mailing list
>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>
>>>>>>
>>>>> --
>>>>> Un saludo
>>>>> Best Regards
>>>>> Pablo Giménez
>>>>> ______________________________**_________________
>>>>> Sidefx-houdini-list mailing list
>>>>> Sidefx-houdini-list at sidefx.com
>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>
>>>> ______________________________**_________________
>>>> Sidefx-houdini-list mailing list
>>>> Sidefx-houdini-list at sidefx.com
>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>
>>> ______________________________**_________________
>>> Sidefx-houdini-list mailing list
>>> Sidefx-houdini-list at sidefx.com
>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>
>>>
>>>
>> ______________________________**_________________
>> Sidefx-houdini-list mailing list
>> Sidefx-houdini-list at sidefx.com
>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>
>




More information about the Sidefx-houdini-list mailing list