Thin line in outline at vector points

[Mejin]

Hello,

I just wanted to ask if this is a bug or if I did not get something in the past updates... – if I draw a circle – the outline has some strange thin white line at some vectors that go through the outline. You can see it here: (You'll probably have to look very closely)



What causes this? This is very uncomfortable to build a character like this – for example, if you have a Close up of an eye – and then there are these lines... .

Best regards,

Mejin

[Greenlaw]

Is that a screenshot of the workspace, or a rendered image (Ctrl-R)?

The workspace's display can be less than accurate because it's optimized for performance. If the image looks correct when rendered, I wouldn't worry about it.

Hope this helps. If that's not it, post an example project. I can take a look at it this evening (if not me, I sure someone else here will.)

[synthsin75]

I have to zoom in very close to even see the line. I doubt this would be noticeable in animation, only in a zoomed in still frame.
But I wasn't able to replicate this here. Sharing a file with the problem shape might help.

[Greenlaw]

Oh, I was looking at the wrong thing...I see the line now.

This looks like the thin line I get when I split a shape to two layers, and the anti-aliasing causes a slight mis-match at the 'border' edge.

Try this: Does it look correct when anti-aliasing is disabled? If so, that's the problem. With no aa, the pixels should line up perfectly. In the past, I would just render with no-aa and use OLM Smoother to add AA as a post effect. Unfortunately, the current release of Moho isn't rendering fine lines correctly when AA is disabled.

But if the setup is as I described, you can add a point to the line in one of the shapes and simply pull the edge to slightly overlap the edge in the other shape. The overlap 'covers up' the line, and it usually fixes the error. I like to use this trick for elbow and knee joints, in limbs that need to wrap around the character.

BTW, I'm planning a video on how I animate layer sorting for wraparound limbs, and it should cover this technique.

[Mejin]

Hi!

Thanks for your input.
I rendered this via Command+R. And yes, without Antialiasing it works. (But well... looks like you'd think it looks)
OLM Smoother – never heard of this before. Does it work flawless?

About the adding a point to the line – but if I have a circle this would break the 'perfect' circle, right? I can't split an outline and then move the points on the same curvature, or can I (?).

I could put a line on top of the 'broken' line... but... well, that wouldn't be that nice... to animate and rig... .

Best regards,
Mejin

[Greenlaw]

Okay, at least we know what the issue is now.

Re: OLM and rendering without anti-aliasing: It's fairly common in the 2D animation industry to render without anti-aliasing, and then apply anti-aliasing as a post-process effect. This step can be done in a compositing program, such as After Effects, along with the free OLM Smoother plugin I mentioned. I did this with Moho a long time ago, but unfortunately, Moho currently has trouble rendering very thin lines when anti-aliasing is disabled.

So, at this time, I recommend rendering with Moho's anti-aliasing enabled and correcting the line error before rendering.

I don't know why you split the shape this way in your project, but I can show you an example of how I address the white line issue.

For example, I may split an arm drawing into two shapes, and then break that out into two layers...like this...



Which allows me to do this...



But then I see a white line in the elbow, just like in your example...



To correct this, I simply add a point to the drawing in one layer, and pull that point over the edge that's visible in the second layer...



Now, when I render the animation, the white line is gone...



I don't know if this applies in your situation, but maybe it will give you an idea for how to fix it. Good luck!

[Mejin]

Hello,

ah, thanks, I see what you mean – yes, in this case where two shapes should 'overlap', this is totally a good way. But here's the strange thing – I did not split the circle. It is a freshly "out of the box" ellipse, made by the shape tool – and these lines are sometimes on all vector points. It seems that it is only there if I take the "Draw Shape" tool and draw an ellipse. If I draw a perfect circle, it is not there. As soon as I change the shape, the white lines appear. (As well If I to this with the transform tool)

It seems like if I draw an (imperfect) ellipse by hand via "Add point" it does not happen.

Strange.

All the best,
Mejin

[Greenlaw]

Hi Mejin,

That is strange, as I've never seen the gap when drawing an ellipse with a hole. Is your shape made of two ellipses stacked on top of each other? If so, just create one shape using both paths, and the center ellipse will automatically subtract the center.

Here's a quick demo...



If you haven't watched it, my tutorials on drawing vector art in Moho explain this technique.

If you must split the top side of the ellipse for a reason, split it into two shapes by adding another segment at the bottom, and create two shapes from it. You should not see a white gap in either segment when you do this, so long as the shapes are in the same layer.



Typically, however, splitting the shape shouldn't be necessary unless you need to stack other shapes between the ellipses' sides. (For example, an item passing through the hole.)

I hope this helps. If none of these suggestions apply, could you post the file for someone here to look at?