Houdini lava bomb effect.

[hug03018446]

Hello everyone. I am very much a newbie to houdini and I'm looking at houdini to make some effects for a project that I am working on. I am looking at setting up an effect for some lava bombs like the ones from the movie Pompeii, they are the bits of lava and rock that get spat out by the volcano. here's an example. 

 

So my question is basically, how would one go about creating an effect like what we see here, mind you that a single trail is ideally what I'm after and not a whole bunch of them. I have had a play with setting up a simple sim using the off the shelf pyro tools and run into problems very early on with using an animated object as a fuel source. If anyone could point be in the right direction I would be much appreciative. the size of the source I'm aiming for is quite large maybe 2 or 3 metres in diameter.

 

If there are any tutorials that could possibly help me out the please direct me to them because I have not been able to find out how to create a simulation of this nature.

 

Thank all,

 

[Farmfield]

I would probably do a couple of sims, cache them as VDB's on disk and then start stacking. There's a lot of trickery you can use to remove the duplication look, like using noise on top of your sims, shifting timing, mirroring them in different axis, etc...

[woodenduck]

Here's a basic setup you could start with. I like to break these things down in to separate sims. Firstly create your rbds (or maybe viscous fluids if you're doing lava) or whatever your source might be. Then unlike my scene I would cache that to disk. Then use this to generate some particles for the pyro source. Cache these also. Then create a fuel volume from the cached particles and bring this in to a pyro setup. 

 

The scene I created is just to give you an idea of the workflow. (My workflow, at least. I'm sure everyone has their own ways). This is very much a starting point. You could add multiple particles sims for fuel source, to render as debris/dust, to instance small rocks, you could also advect some through the pyro velocity field as burning embers. There are a million things you could do to the pyro sim. The world of pyro is vast and complex. Playing around with the shape and combustion tabs is a good place to start. Also a dull looking sim can often be brought to life with some time spent noodling around in the pyro shader. 

 

Hope this helps you get started. Good luck! 

 

WD

pyroTest.hip

[hug03018446]

Thanks for the replies Woodenduck and Farmfield. 

I have had a look at your setup and it looks like a great starting point, I didn't actually think about using particles as a fuel source. I'm going to do some testing to see what I can do with it. Many thanks.

[hug03018446]

Hi guys, 

 

I tried sourcing from geo firstly but never got anything usable because of the speed in which the rock travels in the scene, I then thought that sourcing from particles emitted from the rock would give me some better results however, I'm having some problems getting that working. I would be very grateful if someone could have a quick look over my file and show me where I'm going wrong.  

 

 

I'm not sure how to upload my scene here on the forum so I have a link to the external file.

Keep in mind that I am very new to Houdini so don't be too shocked by my silly mistakes.

 

https://drive.google.com/file/d/0B0DfVAcbxuwbczhrZ3VEQjNyeVU/view?usp=sharing