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# Twixtor and depth of field

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 Twixtor and depth of field on Mar 16, 2013 at 10:41:49 pm

Hi, this is the first time I post on this forum so I introduce myself.

My name is Giovanni and I'm and Software Engineer with passion for Photography. I use Twixtor Pro together with an array of cameras to produce 3D pictures to print on lenticular medium. This is my website where you can have a look at the result: http://www.framedlives.com

Now I have a question. All my pictures are sharp, with infinite depth of field. I recently tried to simulate a shallow depth of field using RSMB together with Twixtor. I'm able to move the sharp plane back and forward and increase or dicrease the depth.

Of course this is a trick, not a real depth of field. The result is good but not perfect because the blur is clearly along the horizontal axis and not both axis. Is there a way to create a blur along both axis even if my videos move along the horizontal axis? Maybe manipulating the exported vectors from Twixtor?

To summarise I would like to blur a video uniformily along both x and y axis using the information of movement along the x axis.

Any idea? Thanks,

Giovanni

 Re: Twixtor and depth of fieldon Mar 17, 2013 at 12:29:14 am

I maybe found a better solution in After Effect.

1 - I extract the Motion Vector using the "Motion Vectors: Create" plugin coming with Twixtor Pro.
2 - Then using a "Channel Mixer" effect I extract the horizonat movement only, i.e. the red channel.
3 - Eventually I use this red channel as a Blur Map for the "Camera Lens Blur" effect.

Giovanni

 Re: Twixtor and depth of fieldon Mar 18, 2013 at 4:57:09 pm

Nice work by the way,

You can do what you say,
Just be careful that we map zero motion to 0.5 (so 0 becomes -MaxDisplace and 1.0 MaxDisplace)
So you can do a difference to a solid layer set to 0.5, 0.5 to turn that into an absolute value.

I am not too familiar with AE Camera Lens Blur, in case it has any use for you, in our SmoothKit ZBlur we allow you to remap such greyscale image. I am mentioning as I am not quite clear about your camera configuration - i.e. sometimes objects closer to camera will have opposite disparity then something further away and you might not want the foreground to be blurred...

Pierre

 Re: Twixtor and depth of fieldon Mar 18, 2013 at 5:35:36 pm

Thanks for the link and the note about 0.5, I actually missed that point.
The Depth of Field simulation works pretty well with Twixtor Pro + AE Camera Lens Blur.

To actually select object moving in one direction and object moving in the other direction, i.e. background and foreground of the stereoscopic window, it is enough to use the Subtract blending mode instead of the
Difference blending mode.

Thanks,

Giovanni

 Re: Twixtor and depth of fieldon Mar 18, 2013 at 6:09:29 pm

In case anybody is interested, this was my success in creating a Depth Map using Twixtor Pro and After Effect. Using the Depth Map and a Lens Blur filter I can select the focal plane and the level of blur in post production

The more I use Twixtor Pro the more I love it :-)

Giovanni

 Re: Twixtor and depth of fieldon Mar 18, 2013 at 6:27:21 pm

Cool

In case for an application like this:

1) One can set Vector Resolution to Full Res for finer edge details
2) Try Sensitivity 100% instead of Default

Pierre

 Re: Twixtor and depth of fieldon Mar 19, 2013 at 9:25:51 am

This is a final example of selective focus obtained in post production using Twixtor Pro.
Twixtor Pro is good not only for videos but also for still photography.

I have two pictures (left and right) of the same subject taken at two different angles - Pictures copyright Giovanni Remigi

left.jpg

right.jpg

Using these two pictures and the motion vector generator coming with Twixtor Pro, together with After Effect blending modes Add, Subtract and Difference, I can generate the following Depth Map.

depthmap.jpg

Finally, I used the generated depth map and one of the original pictures, together with the Lens Blur effect coming with After Effect, to generate a shallow focus centered on the eyes.

blur.jpg

Enjoy,

Giovanni

 Re: Twixtor and depth of fieldon Mar 20, 2013 at 3:39:37 pm

This is yet another application of Twixtor Pro for still photography and 3D imaging, this time together with Blender 2.6.

The previously generated depth map has been rendered in Blender after the application of a Displacement Modifier using Cycles engine.

3d.jpg

Giovanni