Particle problem

[slowtiger]

I have a car drive into the scene, then break down in the middle. At that moment smoke should start to emerge from it. Because particle start can't be animated I place the particle layer outside, then move it to the right place within one frame when the car begins to burn. (Switching visibility is not an option because it will show the whole smoke column at once.)

Some smoke particles blink: visible in one frame, vanish in the next. (Life is set long enough.) It seems to happen stronger when I move the particle layer in one frame, when I move it in slowlier there's less blinking, but still.

1. Why does it blink? (Maybe the change position randomly, I can't tell.) How to stop?

2. Is there another way to make particles start in the middle of a scene?

[synthsin75]

You can animate particle start. From the particle tool, disable On at start and then check the Particles On box when you're on your start frame.

[Greenlaw]

Wes beat me to it, but here's an example...



Project File: TireDust.moho

The circle on the ground is the emitter. Make sure On At Start is off, then keyframe where you need the emitter to come on and/or off. I also animated the transparency of the emitter to fade out the dust. For a little more realism, I guess you could fade it in and out over the life of the particle at the Style level so they don't all fade at the same time. (I feel like I've done something like that before, if not exactly as described.)

[slowtiger]

Ha, that worked! Thank you!

To complete the tip:
for those who only have the barely necessary channels visible in the timeline, you need to switch on the channel for particles first.

Go to "View > Timeline Channels..." and click "+" at the particle icon.

So this scene's problem is solved. Still the original problem of flickering remains, I don't think it should behave that way. I had an idea: maybe it makes a difference wether I render to Quicktime or as an image sequence, but right now I don't have time to investigate. Maybe later.

[Víctor Paredes]

To complete the tip:
for those who only have the barely necessary channels visible in the timeline, you need to switch on the channel for particles first.
Go to "View > Timeline Channels..." and click "+" at the particle icon.

This is not really necessary, unless you really want that channel to always be visible.
By default, any channel will appear in the timeline as soon as it has animation.

[slowtiger]

Ah, I overlooked that there's a particle tool! Yep, it's all there and works.

(That tool is there since at least v9. I feel dumb now.)

[Greenlaw]

Sounds like you got it worked out, but here's a tip if you see other irregularities with the Timeline Channels:

If you updated directly from an earlier version of Moho 14, the Timeline Channels Settings may need to be reset. I made a video about it here...

Troubleshooter! Moho 14.3 Timeline Channels Fix!

Hope this helps.