Moho Forum

Hi all!

I'm testing out Modo at the moment and running across a visual bug that seems to occur on export. If I put a brush effect on a stroke, it appears to get clipped once the animation is exported.

To demonstrate, I've drawn a basic triangle on a vector layer in a new file. I've then applied a watercolour brush effect to the stroke of that shape:



If the layer is selected, playback within Modo is fine - I've got line boil and various other settings on to give it a bit of randomness. However, once exported, the effect is clipped by some kind of invisible mask:



If I scrub through the render, you can see that the invisible mask stays in the same place:



Nothing I do seems to have any effect on this clipping. Shrinking the size of the stroke also seems to reduce the size of the invisible mask along with it, so clipping still occurs (It's less noticeable at a smaller scale, but it's definitely still there). The invisible mask also doesn't seem to correspond at all to the frame that shows when you select the object in Modo (that particular frame is actually a lot small than the invisible frame). Some brushes are more affected by it than others - here's a different brushes with a less noticeable clip:



I'm not entirely sure how the brushes work, but given they seem to be a static image that's duplicated, scaled, rotated, etc along the stroke path, is there a chance that the frame these individual brush images are sitting are not rotating along with the brush itself? So rather than the brush image and its individual frame being rotated as one object, the brush image is being rotated inside a square frame while the frame itself stays the same?

Can you post a file with an example of the problem?

My guess: it happens because of its proximity to the project boundary.

Could you duplicate the project, double the project size, then reduce the content by half, and test again?

I've tried a few brushes with various settings (line boil, random etc ..) and close to the render area edge, but I can't yet reproduce the issue. As Wes has suggested, if you could upload a file...

How does it look in a render preview (ctrl-R)? If it looks good in the render version, I wouldn’t worry about as it’s probably just a display optimization artifact. Some artifacts are deemed acceptable in favor of having faster UI and more accurate playback performance, when they don’t affect final render quality.

If it looks like that in the render preview, or more critically, in the final render, then it’s a serious issue.

Tip: this may or may not help, but try disabling or enabling GPU caching in Moho’s Display Options list. Sometimes this works for me when a display artifact is too distracting, like the shading error I demonstrated in last week’s Moho Physics tutorial.

Hope this helps.

The clipping occurs in the rendered file, not in the Moho interface. In answer to other questions, it happens regardless of how close an object is to the border of the project file (and honestly, regardless of how close it is, it should not happen anyway).

I will get a file uploaded when I’m back on my machine but I might do a full uninstall and reinstall first - I had previously had Anime Studio installed from way back so I’m going to try and purge my system fully of anything related to Anime Studio or Moho and try again.

... and if you're using a brush that isn't in the standard factory set - could you upload that as well please!

TheMinishLink wrote: ↑Sun Mar 02, 2025 10:15 pm The clipping occurs in the rendered file, not in the Moho interface...

Thanks...just wanted to be sure.

Like the others here, I haven't seen this specific error yet, so, yes, if you can upload an example project where this occurs, and any custom brush you're using, that would help.

FWIW, I sometimes see poor edge quality when using stock and custom brushes, and it's typcially related to how the brush's transparency is being applied. What I'm referring to happens only with some brushes, and it looks different from your example, but maybe it's related?

I think I corrected this by creating actual alpha channel data for a brush rather relying on luminance. But it's been a while since I looked at the issue, and I should check my notes.

Ah ha! Solved - it looks like some old installations of Anime Studio/Moho and their respective content folders were the issue. Went through my machine and purged everything I could find and reinstalled it all from scratch and I'm now no longer getting the clipping on export. It was probably an older version of a default brush that didn't work correctly.

Many thanks for everyone's assistance!

Ah! Cool. I'm glad you solved the problem. And thanks for sharing what you found!