There's been a handful of reports where "obviously" not a UDIM filenames
were detected as such during image open.[1]
This change makes the detection less aggressive by enforcing that the
4-digit sequence be delineated on both sides by one of the following 3
characters ., -, _
This fixes the problem for such filenames as:
"screenshot-1080p.png", "Image-1920x1080.png", "(1999) Photo.png", and
"antiguaChestnut_X_1240Wx814H.png"
[1] T97366 T98918 T99154 T100035
Differential Revision: https://developer.blender.org/D15573
There are some filenames where the UDIM pattern guessing would fail
unnecessarily. The user can fix these up afterwards but it would be
nicer if they would detect properly in the first place.
Examples:
`test.1001.ver0023.png` would guess wrong since it uses the image
sequence detection code which finds the first sequence from the end. It
would guess `filename.1001.ver<UDIM>.png`
`uv-test.u1_v2.png` would fail detection due to a bug in the processing.
Make this much more reliable and add tests for the most important tile
related get/set/detection functions.
Differential Revision: https://developer.blender.org/D14320
