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younglegend

Animate parameter per cluster

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Posted (edited)

Hello ppl! Have a question about pyro clustering that i've been thinking about for a long time now.

So i have multiple explosions on impact and i'm using pyro clustering for that. How do you animate parameters per cluster? For example i need the timescale to be 2 when an explosion starts and gradually come down to 0.5 after few frames, but per cluster. Any ideas on how to approach this?

Unfortunately i can't share my scene file. But you can find the similar setup here. Thank you!

Edited by younglegend

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I think a good approach for you would be to develop a sort of "master" sim that has the look of the explosion you want. Or, if they are to be drastically different, maybe 3-4 main sims. 

You could then run them as wedges, changing different "seed" parameters (like seed and offset in various noises, etc) to get different slightly different looks. 

If you name them like

explosion_$WEDGENUM.$F4.bgeo.sc 

you'll get a set of explosion sequences. Then you can scatter some points, and give them some random rotations about their Y axis (just turning one explosion 90degrees can sometime give you as totally different looking explosion depending on the camera!) 

You can load the vdbs as a packed prim and use an "activation" or "index" attribute to say what frame you want to the explosion to start on, and set the unexpandedfilename intrinsic to load different frames on the points

(see toadstorm's post for a better explanation at the bottom)

Loading the caches in as delayed load VDBs will be quite efficient at rendertime, too. 

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Thanks for the suggestion James. Wedging was my first choice as well but unfortunately i have to stick to clustering because i'm overriding division size per cluster, based on the distance from camera.

And if i carry on with wedging, i might have to do multiple wedges with multiple resolutions which just keeps consuming more time and my limited disk space. (i have like more than 15 explosions atleast)

That's a great article by the way. Cheers!

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Hmm I see what you're saying. But would it be difficult to just sim 3 levels of detail? Like a lo/med/hi and assign that as an attribute to your instance points so it picks up the right foreground/midground/background sequences?

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Posted (edited)

That's the only choice i guess....and let it render over the weekend.

The dop is reading attributes like scale, cluster and div size which is assigned outside the simulation and somehow applying it to each cluster container. Trying to figure out how to bring other attributes like timescale, the same way before taking the long route.

If it was pops or rbd, assigning attributes outside the sim will override or multiply with the dop attributes.

Edited by younglegend

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I think if your shot is laid out, and you know where the explosions are going to go, pre caching a few and either scattering or hand placing them ia the most flexible route. If you or your sup don't like a certain sim, it's easy to just swap in a new one or add more in certain places and rotate/scale them

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