Particles emitters are not started when out of frustum

[Amerio.Stephane]

Hello,

It looks like particles emitters are not started when being out of the active view frustum.

This is especially problematic in a multichannel environment. Typical use case:

1. Helicopter SAR mission over the sea, looking for a distress signal
2. the sinking ship launches a distress flare (this is expected to create a highly visible smoke column and a bright light at the top)
   This is typically made by spawning a new particle emitter on the boat
3. If the boat is already in the frustum, then the effect is visible. Otherwise, if the boat comes into the frustum later on, then the effect is either not visible, or suddenly re-starts. In this latter case, some particles are just 'jumping' from their last know position to their actual position, creating very bad looking trails.
4. If the boat was visible on one channel, but not on the other, then the effect will appear as 'clipped' where the channel visually joins

How can we force a particle effect to always be computed, no matter if its too far, or outside the view frustum?

 

[silent]

Hi Stephane,

Particles (as well as MeshSkinned) can be force updated outside of the bounds by using the built-in "Periodic update" logic:

• https://developer.unigine.com/en/docs/2.20/objects/effects/particles/#optimize

So, basically it should be enough to set Update Distance Limit to inf and set some FPS value in FPS When Object Is Not Rendered At All field. Of course, you can do it via API as well.

Thanks!