Geometric Anti-aliasing and shudder
Posted: 31 March 2021 03:21 PM   [ Ignore ]  
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Joined  2019-07-21

I am wrestling with the help manual.

I want to pan across a collage of photos - which naturally have straight edges. With anti-aliasing turned off, the TIFF sequence “shudders” on playback - as if the player can’t read it off the disk fast enough. Slight starts and stops make it look jittery. I thought it might be improved with anti-aliasing, but that seems to add a smearing artifact even at somewhat higher settings (Best/1x1/4x4/5%/Catmull/200%). See attached file S203. I switched to Geometry at 200% MIP and still get the smearing (see attached file S204). So my question is, am I overlooking something very fundamental? Or is it impossible to get a smooth, jitter-free “Ken Burns” motion pan using Cinema?

I’ve tried every filter and setting I can find in After Effects and Premiere to try and smooth it out, but they each add a crummy artifact of their own, so things sort of stack up. Seems like it should be able to work straight out of Cinema without fussing with Adobe settings.

Sorry - don’t need you to spoon feed me. Just point me in the right direction and I can sort it out. Right now I’m staring at a blank wall.

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Posted: 31 March 2021 05:26 PM   [ Ignore ]   [ # 1 ]  
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Hi fordmar,

Without knowing the settings, it is pure guess-work, not really what I like to do.

As usual, I just need the file, no need for the images.

Cheers

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Dr. Sassi V. Sassmannshausen Ph.D.
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Posted: 01 April 2021 02:23 PM   [ Ignore ]   [ # 2 ]  
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P.S.: Do you need an upload link?

OK, some guessing/suggestions:

If it is a texture on an object or an image on a flat polygon, it is the same story.

If you think it is the playback speed, use a jpg sequence to test it. Typically Ae should do the trick with its RAM preview (similar to the Picture Viewer.

I see some interlace artifacts(?) hard to tell based on the small image.

Motion blur is often needed. Since the images above can’t show the speed of the motion, hard to tell.

If you have access to cinematography books, perhaps check their suggestions about panning. It is helpful to stay below a certain speed.

All in all, scene files would give me most of the information I need to answer appropriately.

Cheers

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

Photography For C4D Artists: 200 Free Tutorials. Texture, Panorama, HDRI, Camera Projection, etc.
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Posted: 08 April 2021 12:28 PM   [ Ignore ]   [ # 3 ]  
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Joined  2019-07-21

Most of the artifact issues were reduced by using Physical Rendering. But of course that’s a very slow approach. I agree the panning speed is the biggest factor. We have settled on a rate that minimizes the artifacts for the moment.

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Posted: 08 April 2021 12:43 PM   [ Ignore ]   [ # 4 ]  
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Thanks for the update, fordmar.

If you have the ACS (American Cinematographer Society) manual available, there are guidelines about panning speed.  But yes, since 3D renderer often do not deliver motion blur by default, the render-time increases if that quality is enabled.
Since I had no file to evaluate, the fastest method might be based on a Motion Vector pass, if the motion is linear, that is often a good quality. The Vector pass should be 32bit/float and many applications can do it by default or via plug in.

My best wishes for your project.

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

Photography For C4D Artists: 200 Free Tutorials. Texture, Panorama, HDRI, Camera Projection, etc.
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