[Feature request] Non-Inherit velocity toggle for SoS

Hello, recently I have been having some issues with making small shell-of-shell effects, which are often used in minor fireworks displays. The main issue is that shells’ inherited velocity is quite high and while in some cases this is a great thing (I am thinking of shell of shells waterfalls!), in many other cases it is quite frustrating and can ruin immersion and realism. While it’s true that in reality, a shell of shell has indeed some inherited velocity, I feel that it is too much. So, my feature request is to add a checkbox or a slider for determining if and how much the sub-shells inherit the velocity during the explosion.

I added below two pictures showing the aforementioned issue. The shell in question is a 100mm blue and silver mosaic stutata by Parente Fireworks, of which the main cylinder shell breaks up at 2.7 seconds (impossible in FWsim due to how poor the effect looks for the fake deflagration) and the sub-shells detonate after about a second or so.

Picture: The desired effect

Picture: Result in FWsim

Thank you for your attention! I hope this is a feature which may be easy to code and it would open up so many possibilities.


Wow! How did you do that? Did you request to Lukas?

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The picture above is taken from a screenshot I found on Finale 3D, but the one below is by using a shell of shells with two set of stars, one invisible ones with the silver trail while the other is strobing.

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Thanks for your input!

If I understand correctly, you are asking about the transfer of velocity from the parent shell into the smaller sub-shells. I just checked, and it seems to me that no such velocity transfer is being done by FWsim.

Here’s how to check:

  1. Open the effect editor
  2. Create a new shell-of-shells
  3. Make it explode very early, for example at 1 second
  4. The subshells move uniformly from the explosion point, and it does not seem like velocity is being transferred (otherwise, they would all be moving upwards).

So perhaps I am misunderstanding something. Could you send me your effects file? I’d be happy to take a look at this.

of which the main cylinder shell breaks up at 2.7 seconds (impossible in FWsim due to how poor the effect looks for the fake deflagration)

Could you send me a video or screenshot of that, or describe what you are seeing?


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Thank you for the very quick reply! So, I tried as you instructed, but I think I misunderstood what you meant. This is the result I get

The effect shape for the kamuro is supposed to be spheres. Maybe more than the “velocity” the shells are inheriting the vector of the shell of shells

What I would like to achieve is the following (on the left side, compared with the effect I am experiencing)

After exploding the shells could breakup in their pattern, as if they were a standard shell fired vertically (rather than from an angled vector)

Please let me know if you have a solution that I can use with the required height and prefire (80m high, 2 seconds for the breakup and about 1 second after the single shell explosions)


Mangmod, I’ve played around a bit and found:

  • You can achieve more spherical explosions by increasing the explosion energy of the secondary break
  • You’ll then adjust the relative speed of the stars to control the size and scale of the breaks.
  • The caveat is that you’ll consider turning off the explosion sound to avoid the boom of the stronger explosions. Until there is another work around that lets us keep the sound subdued in some way, this is the only solution I have found.
    I’ll also say that the larger you try to make the effect, the more this method becomes less effective.
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Thank you for your tip!
It definitely comes handy when working with shells without a trail, giving it a slightly more realistic look, but with tails it’s still not ideal (see pictures below, colours are just for demostration:)

The ideal (mock-up) result is as follows:

Thank you for all your help and patience!

Thanks for the explanation. I’ll look into this!

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Could this be solved by introducing a slider for drag?

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Sorry for the bump. Recently I’ve been wanting to create some shells of shells, but this issue is a bit of a problem so I would like to ask if there are plans to add an option to allow for the example above.

Two video example of the goal I am trying to get are these:

Thank you for your attention.

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Thanks for the reminder! Unfortunately, we haven’t had time to look into this. I’ll let you know when we have updates.

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