[Forum admins, this may be better as a Discussion Topic than Question, please change if you prefer.]
I am using exposed Parameters in Actor Blueprints to drive UV Textures (rotations, scalings etc.), via Materials Parameters defined in Materials Graphs of various Materials. (I’m also using generative algorithmic driving of them, but that’s not shown here.) This is for artistic visuals video content creation (not for gaming).
It works nicely for slower rotations, but when I make the rotations “too fast” I get strange artefacts.
I prepared a quick annotated and narrated TEST screencast recording video using ScreenFlow to capture the issue. I used ScreenFlow because I don’t know yet how to capture the parameter changes using TakeRecorder.
The TEST issue capture video is just over 4 minutes long. (Please excuse the croaky voice have a bad cold.) It shows first a 4K (not PowerOf2) Video mapped to a surface (happens to be Mt Everest) with UV driven rotations, then a photographic JPEG image (4096x4096 PowerOf2) UV texture rotation, both captured from an LG UltraFine 5K display as 2nd monitor. It then shows the JPEG image rotation case capture from my M1 Max MacBook Pro Retina 16" laptop display, and for some reason the artefacts are much worse on the MBP Retina.
BTW: It’s easier to see the issue with the Image (from about 2mins into the screencast) than in the Video (first 2 mins), because the Video has flashing lights. The unwanted artefacts are easily seen at around 4mins into the screencast, so just skip to that if you wish:
https://vimeo.com/844184855/2efe2de88b
[This is an unlisted Vimeo link and may be removed at some stage.]
Some possible relevant Materials properties settings are:
Material Domain: Surface
Blend Mode: Opaque
Shading Model: Default lit.
In the Materials Graphs only the Base Color is connected.
The quick tests shown were done before I learned about Materials Functions. For some reason, when I capture the UV rotation (and UScale and VScale driving) in a MaterialsFunction the artefacts appear even worse (not shown), it looks like some kind of unwanted video feedback trails.
I welcome any advice on how to best tune such UV parameter driving of textures, and which settings to best use, as I am going to make very heavy use of it with lots of different videos and images.