(snowy) effect help

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5Diraptor
Met Resolume in a bar the other day
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Joined: Wed Aug 11, 2021 07:45

(snowy) effect help

Post by 5Diraptor »

I'm looking for some help with effects, I have a few questions:
  • Snowy is great, but are there any other plugins that interact with the video layer in similar ways? Most effects just overlay or change the input color whereas snowy seems a one off in the way it stops on edges etc?
  • Similar to above, can particle system be made to act like snowy so that particles will stop at an edge?
  • Can I change the snow in snowy to a custom particle shape / image etc?
  • Lastly, I'd like to understand how the Snowy effect works. Is this deeply built into Resolume and not something that's easy to reverse engineer? I was thinking about rebuilding it in Wire to give me an understanding of how it works and to give myself custom options, not sure how feasible this is though?

edwin
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Re: (snowy) effect help

Post by edwin »

The Snowy effect is indeed quite a custom one. I made it years ago as a Christmas Present, it was still a FFGL plug-in at that point. Because it turned out to be quite popular we made it a built-in effect.
It performs an edge detect and downloads that image from the GPU to CPU, the snow particles are animated on the CPU and i use the edge data to determine wether a snow-flake should continue to fall or not.
The Sparkles effect works similar, that spawns particles at the edges that are detected.
Right now Snowy or Sparkles will be hard to recreate in Wire as it does not support read-back of pixels from GPU back to CPU.

The only thing i can do for you is to see if we can allow custom images for the Snow and Sparkles effect. For the rest i'm afraid i can't help you any further.

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Arvol
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Re: (snowy) effect help

Post by Arvol »

edwin wrote: Sat Oct 23, 2021 15:02 The Snowy effect is indeed quite a custom one. I made it years ago as a Christmas Present, it was still a FFGL plug-in at that point. Because it turned out to be quite popular we made it a built-in effect.
It performs an edge detect and downloads that image from the GPU to CPU, the snow particles are animated on the CPU and i use the edge data to determine wether a snow-flake should continue to fall or not.
The Sparkles effect works similar, that spawns particles at the edges that are detected.
Right now Snowy or Sparkles will be hard to recreate in Wire as it does not support read-back of pixels from GPU back to CPU.

The only thing i can do for you is to see if we can allow custom images for the Snow and Sparkles effect. For the rest i'm afraid i can't help you any further.
Will wire support GPU>CPU data flow at some point? I've been wanting to analyze textures to build out some vectorscopes and that would be a key element to make that work :)

Menno
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Re: (snowy) effect help

Post by Menno »

preferably no, probably yes. We'd like to hold off on gpu->cpu downloads for now as undelayed downloads cause full pipeline flushes where the cpu has to wait for the gpu to complete and then the gpu having to wait for the cpu to provide more work resulting in the machine doing a whole lot of nothing for a while. We'd need undelayed downloads when they're done mid-frame for a result that makes sense logically.

We could do delayed downloads but it needs to be obvious that this is happening so that it's clear that it can be used for driving some graphics or w/e but not for logic. Additionally we might provide compute support which could enable some evaluations to happen on the gpu, outputting their results into gpu buffers which can then be used by other gpu based nodes.

In the end if you want to send a pixel color out over osc or something you need to have a download so we cant get around that, but yeah for the other cases it's probably better to have the tools of choice available before providing the clown shoes enabling you to stumble over your own feet.

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