Lava bubble popping effect

n4uj

Hello fellow Polycounters

About one year ago, I read a very good article/post about a technique about how to make a cool lava bubble popping effect. I thought I read it either at Polycount or at Simon's Schreibt blog, but I couldn't find anything using the search engines of both sites. And now I'm trying to figure it out where did I find it, since I need to do a similar effect.
Does this ring a bell to any of you guys? Help would be much appreciated

Thank you in advance!

Juan Moraga.

Mark Dygert

There are a few different ways you can do it. 

Scale and Translate: Pretty much self explanatory. Slowly scale and move it up, tremble it a bit, then quickly scale it down. As it pops if you squash it vertically and scale it horizontally you can get that dimple effect just before it pops and the lateral movement gives the impression that it popped.


This same idea can be done with morph targets also. Unreal has the static mesh morph target system, that bakes the vertex animation into 3 uv channels of the mesh. Because they are static meshes you can use them in the particle system. You can use it to make bird meshes shoot out of a particle emitter and flap their wings, or to distribute bubbles around lava ect... Lots of uses.

OR...

Animate the UV's with an opacity map: This is good for slower pops with thicker material. This one is pretty easy to set up in most engines.

Eric Chadwick

I was looking around for this, I vaguely recall seeing it too. Didn't find it, but saw this 2d anim.

Deconstructing this, it could be done in 3d using an alphatest shader on a hemisphere, plus a particle effect for the droplets, and another for the ripple.

Eric Chadwick

Found a tutorial for a similar effect.

https://stevencraeynest.wordpress.com/2013/03/29/easy-volumetric-explosion-in-unity3d/

n4uj

@Mark Dygert Thank you very much for you answer, those techniques look awesome, I finally ended up doing it with a mesh base particle effect and modifying just the size through time, which is exactly what you adviced me in the first place. I didn't know about the other two, but they look really cool, I'm definitely gonna try them both Whenever we release the game, I will post the final results

@Eric Chadwick Thank you too Eric, for taking the time to look for it as well. Iirc it was something related to vertex paint, and it looked really nice. I hate when I can't find good articles that I read long ago. That volumetric explosion with the displacement method is nuts as well, really impressive!

Thank you both again!

panta

@n4uj I know this is literally like 3 years later, but are you talking about this thread from RealtimeVFX?
https://realtimevfx.com/t/jordanov-sketch-17-wip/6207/6

I hate to necro, but it's crazy cause I remember the exact thread with Simon S you're talking about XD

n4uj

panta said:

@n4uj I know this is literally like 3 years later, but are you talking about this thread from RealtimeVFX?
https://realtimevfx.com/t/jordanov-sketch-17-wip/6207/6

I hate to necro, but it's crazy cause I remember the exact thread with Simon S you're talking about XD

Hahahaha, omg Panta, this is crazy. I completely forgot about this, I don't even remember what post did I read back then (altho I do remember how bad I wanted to find it back) so I literally just can't say whether your link is or not what I was refering to xD.

I think it was what I thought, a very clever way to cheat the bubbles by using vertex displacement shading and vertex colour masking, but the memory is so faint. I don't think it was some fancy off-line baked simulation tho, and that one looks kind of pre-made.

Thank you for sharing btw, I appreciate your help!

Jeez it's been quite a while since I last logged into this amazing forum!!