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Can someone explain to me why this happens?

It's gone on for as long as I can remember but I never took the time to ask.
It happens when I use the Distortion-Warp Grid FX. I key whatever movement I need and after applying the FX, well you can see what happens.
And my settings for the FX are set to Smooth and Best method.

It's not always this bad. Sometimes its a few dots here and there.

Yes, i can confirm this.

13 Mar 2019, 14:36 i posted a report on this bug in the Beta forum.

I love the wrap grid tool but it's a pain when you have a long sequence and have to go back over it in whatever color that's screwed.

i agree its a very usefull tool.

What i'd love to see (apart from having this bug fixed) is a custombrush input.
so instead of just the source and destination grid,
have some more options for the source input:
-source grid
-custombrush
-project
- etc....

This has not been fixed in the recent update. Is there a possible fix coming down the pipe?
I don't have the same issue with using the Distortion-Optical tool.
Also, it appears to be a transparency problem. When I create a new layer behind the problem and make it the same color, the problem is fixed by way of a band-aid. Of course its till an issue when dealing with a sequence.

I've had this problem with GIF89a output in TVPaint for years (white noise in the last or several of the last frames), but its intermittent depending on the imagery. For a long time I attributed it to my ACDSee image manager because I have other GIF players which somehow suppress the white noise visible in ACDSee playback.

In the end, I think the problem comes from TVPaint's GIF palette reduction process which determines the best 256 colors for the GIF images based on the full color palette for all frames. Once generated the best 256 are substituted in the GIF, the black pixels in the last frame (or frames) aren't properly reduced... instead, converted to white or more likely, improperly converted to transparent letting the white background show through.

I've had some luck by re-importing the GIF back into a clip, then change all 0,0,0 pixels to 1,1,1 pixels, then re-saving out to a new GIF. which makes sense if 0,0,0 pixels are supposedly transparent?

INFO on GIF (Graphics interchange Format 87a and 89a)

It doesn't matter if it's a GIF or PNG.

Hmm. In my case I've only noticed the noise problem in GIFs and when present, always on the final frames, after export. For me it is a product of Optical Flow distortion so I guess it's two different things...

sven

I believe its not palette nor gif related.

The wrapping grid distortion drops pixels, which creates holes.
I suspect the wrapping grid algorithm needs an overhaul for this to be fixed,
So probably don't expect an improvement fast.

Peter Wassink wrote: ↑29 Mar 2021, 10:45 I believe its not palette nor gif related.

The wrapping grid distortion drops pixels, which creates holes.
I suspect the wrapping grid algorithm needs an overhaul for this to be fixed,
So probably don't expect an improvement fast.

Damn, It's such a cool tool that I hate not being able to use it on larger sequences.

its also weirdly random and funny that some holes don't move!?

here i highlighted the 1 pixel holes using the 'border' FX:

Nice catch Peter.
Other clues...
In the first GIF named truckbed? note that some of the artifacts seem to be organized in a kind of hooked line and maintain relative position as they scale up...
Makes me think there is residual noise in some processing buffer that doesn't get properly cleared...
Also reminds me in a way of temporary "ghostlines" that can be toggled on and off by inverting their values: here's part of a GEORGE command concerning the protocol order of operations for that:

COPIED FROM MIKE'S GEORGE COMMAND LIST:

tv_ghostline 0|1 iX1 iY1 iX2 iY2

[WARNING]
if tv_ghostline is used while a MetaFunction is active (in a plugin), be sure to call it AFTER the Refresh() function from PIKeys

Draw or erase a temporary line on the screen

[PARAMETERS]
0|1 enum The mode
_ 0: draw
_ 1: erase
iX1 iY1 double double The begin point of the line
iX2 iY2 double double The end point of the line

----------------------------------------------------------------------------
I have no clue about how the FX HUD lines work, but I mention this because the superimposed green control lines in the Distortion Warp Grid interface overlay are sort of similar to those kind of "ghostlines"... (maybe this might be something the programmers could look at.)

sven

Bumping this up.

(I noticed this topic has a green checkmark which signifies “solved”, but I don’t believe this problem has been solved.)

Will this issue with the Warp Grid generating artifacts (holes) ever be fixed ? I've been using the Warp Grid extensively on a recent project and it is a real pain to have to go back and fill in those annoying little 1-pixel holes (but it must be done ,because otherwise they will visibly chatter on screen).

D.T. Nethery wrote: ↑11 Dec 2022, 17:14 Bumping this up.

(I noticed this topic has a green checkmark which signifies “solved”, but I don’t believe this problem has been solved.)

Will this issue with the Warp Grid generating artifacts (holes) ever be fixed ? I've been using the Warp Grid extensively on a recent project and it is a real pain to have to go back and fill in those annoying little 1-pixel holes (but it must be done ,because otherwise they will visibly chatter on screen).

Thanks for bumping. It is definitely a pain to have to go back and fix it. Especially when the errors are in tight spots.

Hi all,

i tried to reproduce the issue but without success. I think it can be difficult to reproduce for us because it depends to particular configuration ( source image, resolution, grid size, ...). So i you succeed to reproduce it, don't hesitate to share with us the project if it is possible with screenshot of fx parameters.
It will give us the maximum chances to be able to reproduce the issue in our side.

Thanks a lot