Sapphire NightSky Effect

I tried a small test project using S_NightSky effect.

It uses several expressions for its parameters, and with them I see a strange problems - some of the frames show several stars jumping for one frame and then returning back to their positions in the next frame.
(The number of such frames depends on unknown factors, but I see at least one such frame in the example).

Can someone check the attached project and test whether this situation is reproducible?
Stars-Test.aep (190.5 KB)

Try turning off all the “Twinkle” parameters. That is on by default and turns the brightness of the stars up and down for a realistic “twinkle”, but in your case, it might look odd with the large pan and be causing them to appear to be jumping.


Here is an examples of the “jump” (slowed down).
Doesn’t look like twinkle at all.

I have uploaded two full exported videos here:

I think you are getting hung up on the flicker parameter as well. I should have clarified, turn down ALL the parameters in the twinkle category, there’s a bunch in there, including flicker (which is different than twinkle). Here’s an example of everything off, which will render out just an “always on” starfield.

This should solve your problem. Also, look at all the parameters in any given Sapphire effect, you can get a ton of different results.


Thank you for your answer!

I turned off all the twinkle and flicker parameters, just to be sure.
Have you tried my project? It has several expressions for other parameters, and starfield in it looks different from your video.

Here is a 2-second part.

Do you see the problem?

I see the problem happening in your project. There’s definitely a “jump” at frame 112. Can you duplicate the problem with straight parameter animation? I’m wondering if it is an issue with the expression, or a couple of things combining to cause it. If you can duplicate it using straight animation (no expressions) that would show if it is a problem with NightSky or perhaps something else.


If I remove all the expressions, the problem is not reproducible.
You may see it for yourself if you disable the expressions, there are keyframes with similar (but not exactly the same) animation.
So, there seems to be something with interaction of the plugin with expressions in this case.

The expressions themselves are not higher mathematics. And they don’t contain some kind of unpredictable functions, so I can not understand the reasons of such strange behavior.

Looking through your project, the problem is with your expressions. As a plugin, our params are simply linked to the expression, we couldn’t have a bug there that would cause some sort of unexpected behavior. Now, if you could replicate the behavior with the expression turned off, that would be a problem. But that’s not the case here.

I would say that it’s some interaction of the plugin and expressions.
If you look at the resulting values of expression calculations, there’s nothing there that could lead to such jumps.
But what are the values that the plugin is using? There is no way for me to see, i see only the result - and this result clearly tells me that there is something wrong in the processing of these values.

I’ll direct message you and we can chat about it.