Moho Animation Forum

This is weird. So I have an absolutely perfect cartoon-style liquid pouring out of a jug with particle layers. I had set up with the perfect curve of the particles and all was great. I had 3 different particle emitters, two for pouring drops and lines and a third for the splash at the end. Testing without any motion of the layers was working great.

Then I add the 3 particle layers to a group and bound it to the bone of a hand that is pouring the liquid. So far so good. I then turned OFF "on at start", so I could activate the pouring particles when the hand rotates the bottle to the correct angle. This is the weird thing I can't seem to fix, not sure if it's a bug or a setting. When there is a key activating the particles, they only shoot out with gaps or spaces, in spurts. The particles emit, and then it seems they stop and start again, instead of a smooth flow. When I recheck the "on at start" box the gap goes away and the particles run continuously. I've fiddled with other options in the particle, and this one escapes me.

For now, my only option is to unbind the particles to the hand bone and set the visibility or something turn on when the jug is in position, This is a pain because I can't tweak the movement of the hand that moves the jug like moving it around to pour the liquid. When it was linked to the hand it worked great for that just, it had those annoying gaps in the flow with "off at start" and a key for activation.

Hmm...can you post a stripped-down project with just the emitters and bones? It'll give us something to look at and try. Otherwise, it's just guessing.

I don't know if this helps, but I often make a stripped-down project only to run the particle simulation. Sometimes, simplifying a project this way allows Moho's physics and particle systems to behave more predictably.* Then I'll render the footage and comp it into the character animation, either in the original Moho project file or in a compositing program like After Effects or Fusion. (I usually do this in compositing for more flexibility)

*This is something I do in 3D programs all the time. In addition to more predictable behavior, it can run heckuva lot faster, too.

If you have access to a compositing or 3D animation program, another option is to use the Moho animation to drive a particle system in the other program. My go-to used to be Trapcode Particular in AE, but I dropped it when Maxon raised the subscription fee to a ridiculous rate. (So disappointed with Maxon. I used to be a fan of Trapcode and Zbrush, but now I want nothing to do with these products or Maxon.) As a replacement, I use a third-party plugin for AE called Stardust, which is a reasonably priced one-time purchase. Or, if I'm going the 3D route, I might use Blender or LightWave for particles. Blender works well with the new glTF format. LightWave has issues with Moho's glTF, but Moho's legacy FBX format is a fair workaround for now. (I'm hopeful that Moho's glTF will work with LightWave soon because I'm more comfortable working in this program.)

I got it working. I think at some point my particle layers got "corrupted" somehow?
I had a working copy of the layers that had no gaps and had duplicated it. didn't change anything except the on at start. During some fiddling the gaps started to appear.
I tried setting everything back exactly the way it was copying the settings from the original layers, but no luck.

Finall I simpy copied the orginal layers and set "on at start" to off bound the particle layers to the bone and got... completely different results. It worked exactly as it should. Except for one layer I couldn't get to snap back to what it was doing originally. Even when I turned off bone binding or removed the keys on the particle layers the gaps were there.
I think changing the settings in the particles has some sort of "cascading" effect that is hard to track down. The settings and layers were identical and yet there were huge gaps.
Eventually I got it working but I still have no clue why it broke or what caused it. I am not touching any of the particle settings. Walking on egg shells. I tried it and same thing happened. If I fiddle with any of the settings and try to put them back I get the gaps. it's very odd.

mind blowing deadline, won't have time to post a file, will save to do it later.

There is one thing it might be I don't have time to test. I was modifying settings in the particle options while it played and looped. I could see the changes happening in real time... uh... .er... but not consistently. Sometimes if I stopped and started from frame 0 the particle effects were clearly different from what I had been seeing seconds before. I will confess these layers have a ton of crud going on with opacity keys, rotation movement scaling. Trying to simulate the liguid pouring. It worked when nothing else was going on, once I started to bind to bones and animating the bones things went wonky. It could STILL BE USER ERROR. I will not rule that out. But it was odd that turning that check box off and on had that effect.

Good grief. Now it won't do it. I just opened the "broken file" was saving for later to test how it got like that.

Now the GAPS ARE FREAKING GONE. nothing I do makes them come back. Fiddling and change turning on at start off and on, it won't break. It simply stopped. I have no clue.
It's a mystery. Oh well.

With particles, at least in the workspace preview, it seems the display has gotten more sensitive to scrubbing and where you play from. I find it's always better to start playback from frame zero, to avoid any weird particle calculations mid-stream. Kind of similar to bone dynamics.

synthsin75 wrote: ↑Sun Jun 21, 2026 7:35 pm With particles, at least in the workspace preview, it seems the display has gotten more sensitive to scrubbing and where you play from. I find it's always better to start playback from frame zero, to avoid any weird particle calculations mid-stream. Kind of similar to bone dynamics.

YES YES, I'm starting to believe that was EXACTLY what was causing issues. Many of the problems I encountered was incredibly impossible deadline, much loss of sleep and trying to cut corners. It was so much easier to just let the animation play while tweaking the particles. I recently in last two days discovered that during playback the particles kind of were not playing entirely accurately. Once I realized this and started going to frame 0 first problems went away. Frame 0 always reset the particles but if you loop play sometimes they overlap.

Anyway, PROJECT IS FREAKING DONE!!!! Director LOVED IT. Premiere is downtown at the community theater on the 10th. I am hoping maybe some of the characters I animated might be there in person!!

Nice. Glad you got it sorted. Congrats on the project.