In the render window, I see ugly jagged edges, I have 100% zoom. Where is it from? If you change the size of the window, then they move - then disappear, then appear again!
Every zoom except 2 times 4 times (whihc just pixelate) … will make some lines ugly because it resamples the image… it could be blurred to some degree but that’s not a good idea to look at some render results.
This is not true.
1 I said zoom 100%
2 Such problems should be avoided with better scaling algorithms.
Oh the right side was 100%… hmmm did you rendered with less than 100 %??
This could also be related to some of the clipping settings if i remember correctly.
These are the same images, I just resized the window a bit with the mouse.
I didn’t aks for the resizing after render. I ask wether the render was done at 100% or less (maybe for faster previe like render) than the original size what may (or not) influenced the quality of supersampling the line borders. So i’m searching for an answer for your problem.
Perhaps I am expressing myself incorrectly. I am not English. This is ONE image. One scale. All 100%! Try changing the render window size yourself! And you will see!
Steps in the picture. They appear and disappear constantly when changing the WINDOW, not the size of the picture!
There is something like this:
which may (or not) do have an impact on the lines (just an idea). I’m also not native english but i won’t repost my question. So while i’m still trying to figure out your problem (could be any setting about rendering, for example noise reduction while having low sampling rates) please don’t tell me what i can’t try on your file.
Of course I’m not talking about this! Stop writing the same thing.
Are these ripped imagse from your Viewport in render Mode, or real renders that you resize in the render panel?
In both of these cases you can be sure that they won’t show up in the final image. I don’t know why but when zooming a render in the render panel it immediately turns out ugly. And those pixeled edges remind me of that.
Try saving the image and do the same thing on a normal image viewer.
If it was a post just to chat about how terrible is this feature, please say it from the start.
Bye there, don’t be rude with okidoki,
please and thank you are international 
watch the video. I showed how this glitch works.
Saving the image externally didn’t work out then?
Not really understood, but this is a problem only when displayed in a window.
I’m not talking about showing the image in less than 100% but ask you if you had rendered the image in less than 100%.
And that’s why @Andrea_Cicero ask if this also occurs while watching the image in another image viewer.
For someone who is very new here and the community don’t know much about your experience you seem to be a bit unteachable… Anyway: i found this (https://blender.stackexchange.com/questions/74809/rendered-image-shows-visible-line-strokes-artefacts):
The artifact is called color banding so it may be that your contrasty image just leads to this effect. And assuming that this is not the final image you are the final background may just solve this…
Hence, color banding is especially visible in dark gradients.
No. that’s a different problem. But even here you can see uneven scaling in steps, which should not be noticeable.
You still haven’t answered to the suggestions and if this isn’t really your final render i propose to just don’t bother… “but it should” is cumbersome…
You may have a look here https://docs.blender.org/manual/en/latest/render/cycles/render_settings/film.html and just tweak the pixel filter settings (if it really shows up with an other up).
Usually sharing the problematic .blend file solves any language barriers. Could you share the .blend file?
(You save the .blend file with the viewport or camera position exactly where you see the problem from)
The above if the problem only occurs with some .blend files. If the problem is occurring even with the default cube in the default blender scene, if it occurs in the rendered view mode and you have enough viewport render samples configured, then it may be due to a GPU driver issue. What is your graphics card and OS?
I tried it already:
The OP is also not answering the analising questions to help her/him…
And finally a found an example while answering some other question:
Left side is blender showing with 100%; right side some image viewer with 100%…
Like @Andrea_Cicero asked: is the problems in the image ???.. blender just does have some problems showing the image…
Maybe your images is rendered at 100%. Just some kinks in the viewer doesn’t matter, this may occure also with an 100% image but finaly what matters is:
Is it (and is this your) final image?
From time to time some problems occure which are the people aware of (see https://developer.blender.org/T92903) but can’t seem to replicated…
There is not enough time to lament about all the “but it should” in the world.
(I’m attempted to set this to Solution.)
So he was referring to images in image editor? Apparently Blender never implemented any smooth filter/method for transformations on images. You could report the problem to see what the developers say. The report requires that you share a .blend file showing the problem no matter how simple the .blend file is.
