NAB 2017 Rewind - Andy Needham: Projection Mapping and VFX techniques for Motion Designers
Posted: 04 December 2018 08:39 AM   [ Ignore ]  
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Can someone explain to us how exactly you go about setting up the final render from C4D to import into after effects?
We are working on a court projection project and this has been very helpful, however, we don’t quite know how Mr. Needham got to render the final skewed video shown at 23:44.
We currently have a perspective camera already set up.

Please help!

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Posted: 04 December 2018 09:30 AM   [ Ignore ]   [ # 1 ]  
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Hi Monster77,

My understanding is, that he has had set up the aspect ratio in Cinema 4D, so that the resulting frame contains the floor only. Since this is not an rectangular, it needs to be transformed in After Effects [Ae], which he did with 4 Corner Pinning.

The idea would be always to aim for the best quality, with the transformation, every single pixel becomes newly calculated, which means that the quality goes down. I would render out twice the resolution needed for the work in Ae, then use the “corner pinning” to get it ready for the projector.

See screen capture: you can download this video for a better viewing experience
https://www.amazon.com/clouddrive/share/3MR4VrVFo362nmgtYg5jBdN7InSWaFg95jlUa14uUC1

Let me know if that works for you.

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I would solve that directly in Cinema 4D. See following post. Just in case you are interested.

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Dr. Sassi V. Sassmannshausen Ph.D.

Photography For C4D Artists: 200 Free Tutorials: Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

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Posted: 04 December 2018 09:57 AM   [ Ignore ]   [ # 2 ]  
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My suggestion:

You can get the needed footage without rendering out distorted footage and then un-distort this in Ae. Which means, less work and better quality.

The camera in any set up (this one or the above set up) needs to be where the audience* will be, otherwise the project will not work! I assume the camera projection at a certain point. Then turn down the camera, so the “sensor” is aligned with the floor (parallel). This is a crucial step. It needs to be that way, and was done since over hundred years in “free cameras”.

From there you might need to Offset the target/frustum of the camera, and adjust the field of view, until it is nicely filling your view.

Please have a look at this screen capture: you can download this video for a better viewing experience
https://www.amazon.com/clouddrive/share/F4in9Mt8TcRJibz3ourOa6Tl3mN5PEYm9DlPmUNXnQ3

* I assume the projector is centered above the floor, not in the audience. The effect has a sweet spot, in terms of viewing.

Screen shot with the applied rendering, to simulate the final projection
https://www.amazon.com/clouddrive/share/naFETxhEWlIfTkJ6K6p9MpLPBH51kUk2UTRWOMjKNtI

My best wishes for your project

Cheers

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Dr. Sassi V. Sassmannshausen Ph.D.

Photography For C4D Artists: 200 Free Tutorials: Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

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Posted: 04 December 2018 02:30 PM   [ Ignore ]   [ # 3 ]  
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Joined  2018-09-04

Dr. Sassi,

Thank you so much for your help. That is exactly what we needed. All your videos were very helpful.
We ultimately ran into a problem because we are trying to use Octane Render and the second example you gave us was not working for Octane, but we ended up figuring it out.
In the Octane Render Camera Tag, there is a Pixel Aspect Ratio setting that we ended up messing with, which gave us the end result to the first example you presented. We then used Corner Pin in After Effects. The upside to this was that we don’t lose any pixels coming out of Octane.

Once again, thank you for your help!

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Posted: 04 December 2018 02:36 PM   [ Ignore ]   [ # 4 ]  
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Hi Monster77,

Nice that you found what you needed.

The corner pinning will move pixels in non-full single pixel distances. Which means, pixels will be mixed with each other and the information is smushed. There is no remedy for it, some use sharpening tools after that, which makes it only worse.

Hence why I tried to avoid the Ae workflow at all. But if you oversample, the results should be fine.
I’m not aware if Octane can handle the Offset Y in the camera. (I hope I get some budget next year to get some graphic cards for my mac to see what some 3rd party render can do)

Anyway, sounds like you get closer to finalize your project, which is great!

Let me know if there is anything else, I’m happy to look into it.

My best wishes for your project.

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Dr. Sassi V. Sassmannshausen Ph.D.

Photography For C4D Artists: 200 Free Tutorials: Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

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