Rendering bug on two intersecting shapes

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keisern
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Rendering bug on two intersecting shapes

Post by keisern »

Image

We are experiencing an annoying bug when rendering objects that have two intersecting shapes. Maybe the above isn't the best example, but it shows that an extra bump or pixel is rendered at the point that two shapes share.

It seems to only happen when the shape is convex (look at the heel or back of knee joint, no bump there).

It is more obvious when you have a bigger contrast between the background and the shape. Just looks nasty. Any hope of this getting fixed in the next update?
Halvseint, animated talkshow on NRK
www.nrk.no/halvseint
Genete
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Post by Genete »

It should be useful if you post a file example.
keisern
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Post by keisern »

Here is an example file. If you render it, you will see some artifacts/extra pixel at some of the edges, or a lack of pixels where there should be some.

http://www.machineboy.com/files/pixelle ... oblem.anme

This only applies when using shapes without outlines.

Image
Halvseint, animated talkshow on NRK
www.nrk.no/halvseint
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Rasheed
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Post by Rasheed »

An example file was not really needed, because the example is in the image of the original poster. The problem is in AS that neighboring points in a curve affect the curve between two points. From the image I can deduce that smooth and peak curvatures were combined in the same drawing.

If you vary the amount of curvature, you will always need more points. In fact, in this case you will need at least 10 points extra. I selected the points that needed editing to remove the "pixel error". It is still present, but far less than before, even less if you tweak it a bit more.

Image

It can be called a bug, because true cubic Bézier curves are not dependent on their neighbors. Forum user Fazek is trying to find a solution to this problem and the developer is interested. So things might change in the next version of AS.
Genete
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Post by Genete »

I'll render at home to check it and guess what happen.
I supouse that you refered to problem of outlines when an internal line cross and it is hidden. It appears a hole in the outline. So it surprised me that your example is without outline.
By the way. Have you tried to put the outline thick to 0 unless you have already checked to "NO" if it is shown? I guess that it is a problem of that kind.
Let see your example. This night I'll post again.
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heyvern
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Post by heyvern »

I have never encountered this problem.

Is the "outside" of that vector continuous?.

Here is something I have discovered; if you have "non contiguous" points that are joined and the end point is set to "curved" before joining another cross point, it has this tiny little wiggle which looks like that "bump".

You can peak a point BEFORE joining it to eliminate that "bump".

However, in the example shown, I would not have "separate shapes" in that fashion. I would have a continuous vector all the way around the shape and "split" it across the joint with another splin to create a second shape.

In the image below you see a non contiguous connection. The other points are deleted and you have what appears to be a "peaked" point but you can't smooth it out and it has that bump.

Image

-vern
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Rai López
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Post by Rai López »

I have observed this since the last Improved Render quality update on Moho 5.3, specially when that "Gap filling" feature in Vectors tab was included in the "moho_win32_5.2.1rt2" (see HERE for more details if you want) to solve another more serious rendering problem:
Lost Marble wrote:Moho now does some smart, automatic gap filling in cases where two shapes share an edge. For example, in those cases where an arm or leg is split up into two shapes so that it can overlap itself properly. In such cases, Moho will fill just the gap region without making the whole shape bigger than is necessary.
Even I supposed that it had been discussed there, but not... Well, so you can forget now (I think...) that curves line of investigation and you can try to play with this "Gap Filling" feature (in the Vectors tab of Layers Window (as I said)) to experiment the cause/effect relation in your renders, although I don't know (I think not...) if you'll find a real solution with all this... GREETINGS!
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Rasheed
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Post by Rasheed »

@keisern: I doubt people will notice these errors in animation, unless it's a static object. In the latter case, you should either redesign your object, or use a carefully edited image file.

Anime Studio isn't very well suited for pixel point animation. For instance, you cannot draw straight lines, even if you use the grid. Zoom in enough and you'll see what I mean. Here is a rectangle in normal view and extremely zoomed in (all points are snapped to the grid):

Image Image

Think round shapes, think Saturday morning cartoons.
keisern
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Post by keisern »

Thanks for all the replies so far.

Our design does not use outlines and it is very noticeable at all places where two shapes meet. This would probably not affect anyone who uses outlines on their stuff.

Rasheed: It's not really straight lines that are the problem, it happens with both angular and soft edges.

Ramón: I tried out the vector gap fill options, and it made a small difference but you can still see the extra bump.

I believe this is a bug with how shapes are filled and what happens when they are connected. Usually an outline would hide these sort of rendering artifacts.
Halvseint, animated talkshow on NRK
www.nrk.no/halvseint
elbramtsol
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Post by elbramtsol »

Remember, you can always use outlines with the same color of the fill. :D
Genete
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Post by Genete »

I have to say that the aritifact is small but I cannot avoid it with line same color not adding point so close.
If it is an static shape you can remove the artifact manually after render. If it is part of a animation I think nobody can notice it.
Regards
Genete
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Post by Genete »

I have to say that the aritifact is small but I cannot avoid it with line same color or adding point so close. The artifact always exists. Small but exists.
If it is an static shape you can remove the artifact manually after render. If it is part of a animation I think nobody can notice it.
Regards
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