Jump to content
ForeverMovement

Ice fracture on a trampoline, what workflow would you use?

Recommended Posts

Hello all, 

I want to replicate the effect of ice breaking on a trampoline but I can't seem to get my head around the workflow for how I would go about it, the reference is here:  https://www.youtube.com/watch?v=UxpM2D2i0o4

The trampoline part is easy enough, with a quick Vellum setup I got a decent result. The problem comes with the ice, as I figured, I don't know if it's best to take it through Vellum or an RBD setup. I need it to do a few things based on the reference, obviously the first shatter effect and then smaller breaks afterwords from repeated impacts. I don't believe Vellum can have a setup that consistently breaks down over time over the multiple impacts(unless it's just a very high res grain sim?). The Vellum approach is nice because of the speed of the result and the ease of use. On the other hand RBD is robust and I know there's information out there on breaking pieces into smaller and smaller chunks, but when I attempted to sim using a glass style fracture it would explode with the cached Vellum geometry under it. 

Any ideas or other threads somebody can point me towards to get my bearings with something like this? To create the ice sheet I would just take a stable frame from the beginning of the sim and fracture ontop of that cleaned piece of geo. 

Attached is the base file with just the trampoline sim, as my attempts with both the vellum setup and RBD was very cluttered and made the scene file harder to look through. I don't know why I always manage to bury myself in these weird effects but ¯\_(ツ)_/¯ I can't help myself. 

As always y'all are lifesavers and I can never thank you enough. Cheers.

 

IceTrampoline_help.hipnc

Share this post


Link to post
Share on other sites

Divide and Conquer.

If you want to do everything in one go...goodluck....I'm not at Jedi level so I'll take the Divide and Conquer approach.

Here's my file, you should do it in stages below to get the cache out to proceed to next steps:

01) Sim the Ball and Trampoline by themselves, make sure the active solver (next to brain at bottom) is vellumsolver1. Save out the sim with filecache1 (Save to Disk), then ensure to tick Load from Disk. An extremely simple sim.

02) Now make sure active solver is vellumsolver2. This uses the cached out file in step 1 as colliders. So now the sim is for the ice only...(Ball + Trampoline are simply colliders) not Ball + Trampoline + Ice all active at the same time.....this would be a nightmare to control.

you'll notice I use 'lines' only for the ice and not the orig broken up pieces. This is because it's much harder to make cloth that is 'stiff' as ice. While with Hair, using low res lines, it's easier to make it stiff.

So with this approach, the 1st solver uses a measly substep of 4...while the 2nd uses just the default ONE !!!

IceTramp.gif

vu_vellumtrampolineice.hiplc

  • Like 2

Share this post


Link to post
Share on other sites

Wow, thank you so much Noobini. I did want to do the divide and conquer on the sim but I just got stuck so quickly after I cached it and then did the "what now" sort of thing we all do sometimes. I even used the RBD fracture node to make the glass pattern on my first few attempts but it doesn't work on curved geo so I got stuck there too. I really need to work on my approaches, you made it so easy. I also never thought that hair could be used like that, but it's all in a days learning I guess. Again thank you, you've made my day much less stressful. 

1 hour ago, Noobini said:

Divide and Conquer.

If you want to do everything in one go...goodluck....I'm not at Jedi level so I'll take the Divide and Conquer approach.

Here's my file, you should do it in stages below to get the cache out to proceed to next steps:

01) Sim the Ball and Trampoline by themselves, make sure the active solver (next to brain at bottom) is vellumsolver1. Save out the sim with filecache1 (Save to Disk), then ensure to tick Load from Disk. An extremely simple sim.

02) Now make sure active solver is vellumsolver2. This uses the cached out file in step 1 as colliders. So now the sim is for the ice only...(Ball + Trampoline are simply colliders) not Ball + Trampoline + Ice all active at the same time.....this would be a nightmare to control.

you'll notice I use 'lines' only for the ice and not the orig broken up pieces. This is because it's much harder to make cloth that is 'stiff' as ice. While with Hair, using low res lines, it's easier to make it stiff.

So with this approach, the 1st solver uses a measly substep of 4...while the 2nd uses just the default ONE !!!

IceTramp.gif

vu_vellumtrampolineice.hiplc

 

Share this post


Link to post
Share on other sites
Posted (edited)

for now, RBD can push Vellum around, but Vellum can't push back....(well I don't know how to, maybe Steven Knipping does) so Vellum + RBD would have to be faked...which is why you see my ice not as RBD but just another Vellum object...

I'm sure SESI will find a way to integrate RBD with Vellum in the future....well, one can hope.

EDIT: just on the point of activating which ever solvers (1 or 2) at certain stage...i'm not sure if I have figured right, I think you 'activate' whichever solver means if you then use the shelf tools....it adds to THAT solver network...does it affect what sim you are 'running' when you hit the play button, I can't be certain...as said, I'm not at Jedi level...maybe other Jedis can chime in and clarify.

Edited by Noobini

Share this post


Link to post
Share on other sites

If I understand correctly if you have the DOP selected as your active solver whatever you add from the shelf will add to that network, if you don't have one already it will just create one for you in most cases. But that's just from my experience. The only thing I use from the shelf is lights, camera and smoke trail 95% of the time. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×