Strokes rendering problem

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vealti
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Strokes rendering problem

Post by vealti »

I've working on a new character and trying to give the stroke for it a brush so that it doesn't have that smooth computer look to it. I'm been experimenting with the built in brushes and custom brushes and running into a lot of render issues where the strokes in the final renders look very jagged. (Doing full res, full quality renders, extra smoothing) I finally got a brush that I liked and seemed to render fairly well on close ups, but on full body shots the stroke renders more of a dashed line. In order to get it to render full I have to increase the stroke width where it is too thick for what I want. Am I missing something or are brushes not quite there yet in Moho?

Full body shot with brush on strokes
Image

Full body shot with brush removed from stroke
Image
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synthsin75
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Re: Strokes rendering problem

Post by synthsin75 »

You can't expect closeups and wide shots to have the same line quality...unless you disable Scale compensation. Having a global line width style you can adjust at different, extreme distances can help.
Brushes use images, which are resolution dependent, instead of vectors.

You could try layer outline to compensate. After all, you lose brush detail when zoomed out anyway.
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Greenlaw
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Re: Strokes rendering problem

Post by Greenlaw »

When drawing characters for Moho, I'll often start out with a 'line' Style that is applied almost everywhere in the character. This Style is mainly added to define a consistent line thickness throughout the character that can be changed globally when I need it. (i.e., Setting a specific thickness when close or far. This can be used to make adjustments when Scale Compensation isn't giving you exactly what you need.) You can add other properties like brush texture or color to the Style if you like, but defining Stroke thickness in the Style is probably what I use it for the most. (I'll usually define color as a 'local' property but it depends on the character design.)
vealti
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Re: Strokes rendering problem

Post by vealti »

Thanks for the replies. A global line style sounds useful, I have a few questions on it but will start a new thread for that. For the strokes using brushes, I know the quality wont be the same in close ups and wide shots. At some point as you zoom out the camera or scale down the character I'd expect the brush stroke to lose any "brush" effect and look more like a solid line. This would match up with my experience in other software. That's my question, on my renders the strokes with a brush effect become a dashed line instead of a solid line as they get scaled down. That along with even close ups of strokes with brushes looking jagged made me wonder if strokes using brushes just don't work well in Moho or if I'm doing something wrong.
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synthsin75
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Re: Strokes rendering problem

Post by synthsin75 »

vealti wrote: At some point as you zoom out the camera or scale down the character I'd expect the brush stroke to lose any "brush" effect and look more like a solid line. This would match up with my experience in other software. That's my question, on my renders the strokes with a brush effect become a dashed line instead of a solid line as they get scaled down. That along with even close ups of strokes with brushes looking jagged made me wonder if strokes using brushes just don't work well in Moho or if I'm doing something wrong.
As long as you have a brush applied, Moho doesn't try to second guess when you want a plain stroke, i.e. lose any brush effect. Other software may use vector brushes, which are resolution independent. You might not be able to see a vector brush at a great enough distance, but it's still there. Whereas with raster brushes, anti-aliasing can wipe them out when too small, just like the details of any other bitmap image.
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Greenlaw
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Re: Strokes rendering problem

Post by Greenlaw »

I don't know if this is related to your issue with the brushes but a while back I noticed that textured brushes can have AA issues. The problem was much more noticeable with some brushes than others, but it was always there to some degree. I think it had something to do with the Brushes alpha not being properly anti-aliased or blended. I reported this back when I was working on the 'Puss In Boots' show (using ASP 11, I think) and I wound up choosing an appropriate brush that had the least noticeable amount of AA problems.

I'm not sure this problem still exists in Moho 12 because it's been a while since I last used textured Brushes, but I don't think I saw anything mentioned in the release notes about it. (I should check on this; sooner or later, I know I'm gonna need textured Brushes again.)
vealti
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Re: Strokes rendering problem

Post by vealti »

Thanks. I was doing some testing based on the comments in this thread. It seems to be strokes with a small width (a value of 2 or less for the brushes I've been trying) where the jagged renders appear even on the close ups. A stroke value above that and the close ups looked good. Of course they still break up a some point as you zoom out. I tried to compare the same brush in Photoshop but couldn't get the Photoshop version to draw similar to the Moho version for a fair comparison. The Photoshop version does not break into a dotted line though when scaled way down :) For the project I'm working on I want those smaller strokes so will just stick with no brushes for now.
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hayasidist
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Re: Strokes rendering problem

Post by hayasidist »

An approach I've used to custom brushes is to make sure I have good clear space on the "outside" of the brush .png - e.g. I have a 512px brush - so I only use a circle of about 300 px for the texture - outside that it's all transparent.

another observation is that zooming can change the number of brush images for a given line segment (because of scale compensation?)
chucky
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Re: Strokes rendering problem

Post by chucky »

hayasidist wrote:An approach I've used to custom brushes is to make sure I have good clear space on the "outside" of the brush .png - e.g. I have a 512px brush - so I only use a circle of about 300 px for the texture - outside that it's all transparent.
Hey, that's super interesting, thanks for sharing that. So does this mean that antialiasing is happening within the brush itself and not across the rendered image?
another observation is that zooming can change the number of brush images for a given line segment (because of scale compensation?)
I don't quite follow, so are you saying that a longer lens makes for more or less antialiasing?
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hayasidist
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Re: Strokes rendering problem

Post by hayasidist »

chucky wrote:
hayasidist wrote:An approach I've used to custom brushes is to make sure I have good clear space on the "outside" of the brush .png - e.g. I have a 512px brush - so I only use a circle of about 300 px for the texture - outside that it's all transparent.
Hey, that's super interesting, thanks for sharing that. So does this mean that antialiasing is happening within the brush itself and not across the rendered image?
what I found was that, by taking the brush image out to the edge, it's the edges that produce jaggies; and, in one instance, I found that it looked as though there was some weird wrap-round from top to bottom... I'll see if I can dig that brush out - and if file history has kept an earlier "misbehaving" version.

another observation is that zooming can change the number of brush images for a given line segment (because of scale compensation?)
I don't quite follow, so are you saying that a longer lens makes for more or less antialiasing?
Say you have a line segment that fits 8 brush images in it at default camera position. Now zoom the camera and that number changes from 8. But your question prompted me to look into this more -- I've always just avoided moving / zooming the camera "too much" when using (some specific) custom brushes.

And what I think I now see is that it's the "rendered line length" that controls how many brush images. IOW if (say) you have a line that is at z = 0 - as in a default vector layer - and then pan the camera - the relative z of the ends of the line change - effectively the layer rotates around "y" by the opposite amount of the camera pan - so the apparent line length increases -- so with scale compensation OFF more brush images are used to fill the length (rather than keeping the number constant and stretching the "nearer the camera" brush .png) Sadly, however, with scale compensation ON the same happens but to a lesser extent. example here: http://www.mediafire.com/file/kvmqmjhqq ... p.zip/file

((and BTW -- the leaf brush was designed to be the base layer for a colour overlay -- so to use it as intended, it's "don't tint with stroke colour" and use the strokes as the mask:

group - hide all
> vec - colour/s - mask this; blend=overlay
> vec - strokes using the leaf brush - add to mask
))
chucky
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Re: Strokes rendering problem

Post by chucky »

OK so I was a little confused.
THat file didn't have any zoom at all only tracking.
If you switch to using a zoom instead there is no line length change.
Also if you do use tracking apply ' FAce image plane free rotate' and that will also stop the stretch when using compensation. :D
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hayasidist
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Re: Strokes rendering problem

Post by hayasidist »

yeah - my bad -- dead right - not zoom but pan. I tried the "free rotate" idea - works well for the given layer (scale comp on). but there's relative motion with a bg layer not set to rotate... cure one "feature" and expose another... :? hey ho …
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