I don't do a great deal with surfacing, but that last image looks like you have 2 surfaces overlapping...
Do you have a copy surface in there somewhere? I'd have to agree with Jeremy about an overlap, or a duplicate surface.
Thanks but I don't think that's causing it, cause if I hide it, there's nothing - as opposed to another surface as you would expect if two were coincident. And they tend to look all bitty and weird even before knitting - whereas this is distinctly different colours / tones.
Thanks but I've checked every entity in the surfaces and solids bodies folders, and there are no two instances.
It appeared after I changed Document Properties > Model Display but when I changed them back to default, it didn't change back.
NB: and there has been no ofsetting, thickening or knitting happening.
Daniel,.. I've seen this before as well.. and I don't know what to tell you. It's as if the surface has a visual direction assigned to it (one side is dark the other is light) and as the we all assume, it looks like a overlap or two coincident surfaces... but, it's not.
..in making sure,.. scroll back to where you created it,.. and see if a color was assigned.. delete it or any which have been created.. (sometimes a color becomes consumed)... anyhow.. make sure no colors are assigned.. exit and reopen.. do the same again.. note if any new colors are present.. delete... and again.. exit and see if a new color is assign?...
I personally think it's a bug but,.. hey, I don't work for SW Corp.. they work for me/you/us... and it's clear, they don't seem to care... just my experience.
Thanks for your response!!
I rolled it back and whatever has happened to that surface, it's not something that rolling back affects.
and doesn't appear to be an assigned appearance.
Rolling back DID however cause it to happen to other surfaces (see above and below the top-most surface)
Watch the rollback bar now...
It rolls forward one feature...
Putting the Curves > Split Line in the surface (called 'INSIDE mane split') caused it to change.
So, like you say could be inexplicable...? :-/
Have you tried running Tools, Check on the surfaces to see if there are any geometry problems?
Do you have Verification on Rebuild turned on under Tools, Options, System Options, Performance. If not, try turning that on and doing a force regeneration (Ctrl-Q). This will rebuild everything with extra body checking turned on.
I suggest this investigation because, as Paul suggests, it seems as though the surface direction is not working correctly which may be caused by a bad surface (especially since the visual problem moves around, so it may be a surface upstream causing the issue). If you find no issues with the surfaces, I would suggest uploading the part for others to help troubleshoot, or if you can't do that, get your VAR involved.
Righto I shall try these....