Pyro explosion RND

[Juzwa]

Hello, this is my first post here on this forum!

 

I'm still kind of new to Houdini. I've decided to try to make some cool explosion on my own and spend the whole week on it. 

 

Yesterday I've been playing with a simple sphere and pyro explosion preset. I've added a skylight, volumelight and pointlight on the back. I've done couple of sims in low res and have been playing with pyro shader and mantra. And now I have few questions:

 

1) How can I write out my pyro sim? When I plug in the ROP Output Driver in AutoDopNetwork I get an error "Operation Unavailable in Non-Commercial Edition" on a ROP node. But I have used ROP node before end it was rendering fine. How can I write out an AutoDopNetwork?

 

2) Today I've made some improvements on my render. But I'm getting strange, sharp, bright dots. What is strange that they tend to appear at the end of calculations 80-70% of the render, when the whole image is pretty clean. Like they were some extra rays that go right through the volume.

 

 

Mantra changed settings (~10min render time):

- Pixel Samples: 10x10

- Volume Quality: 2

- Volume Shadow Quality: 0.1

- Transparent Samples: 8

 

3) How can I change my sim source to bullet sim (or rbd)? When I switch the nodes (from a sphere to a dopnet) houdini just crash. So i guess its not that simple. 

 

   

[Juzwa]

Ok, pt no1 is solved. I've managed to find out that it's much better to plug a ROP Outpur Driver after import_pyrofields in import_pyro_build.

 

What about points 2 and 3?

[tony]

Can you post your scene file?

[Juzwa]

Hi!

 

Thanks tony but but I've already found what was wrong. I was using a volumelight with a pretty hight velue. Once I've got rid of it everything is ok. And since I'm not gonna render this with environment there is no point using volumelght right now.

 

I've made some improvements on the shader and I'm pretty happy with the resault. However this is still far from high detailed pyro and this is now what I have in mind. I think I'm gonna start adding different sources now, and start mixing them to get some realistic resaults (on the sim). And then go back to the sahders.

 

this is what i've rendered this morning:

 

https://vimeo.com/108466699

 

And this is what i have in mind:

 

 

 

 

The last one is from Igor Zanic ( this vid: https://vimeo.com/53774979 )

 

I have no idea how  this detail is made of shader. This almost looks like some inverted ramp. Black color for fire at position 1, and then adding some lighter key for position 0.999.

 

This is how close I can get for now:

 

 

And I have fow questions for now:

 

1) How do I make my emitter to stop emit both fuel and smoke in AutoDopNetwork? When I change activation in Source Volume to 0 I dont get any more flames, but smoke is still beeing emitted. When I look at the fuel I see that it still exist when the activation is 0. So I make sense why density is still beeing emitted. I'm very confused. I know I can just scale the emitter to 0 to make sure there is nothing to emit, but it's gonna be pretty paint in the ass, when I start mixing emitters (particles and rbd)

 

2)Upres. I'm confused weather do write out lowres, upres, or both? I got used to fumefx, where you first calculate lowres and then do highres, and they both keep different data and store different files. Does houdini's upres work same way?

 

If your have any tips for me I would be grateful !

Edited October 9, 2014 by Juzwa

[poppy]

Hi, I like your latest image.

 

For controlling emitter, you could either keyframe (or $F==) on activation or source volume scale.

 

For upres, I'm no expert, but H13's pyro was so powerful that you could go straight for hires. Or if you rly want to upres, you could use GasUpres node or shelf tool Up-res.

 

And for SLR, I use Raytrace, I believe it faster than PBR for volume imho.

[lucienfostier]

Hello Juzwa

Very cool work and I like what you have in mind.

Would you mind sharing what you have so far.

Cheers

Lucien

Edited October 20, 2014 by lucienfostier

[Juzwa]

Hi, 

 

Sorry didnt have even a minute time. I just started a new job and its been overhours since then. 

 

Here are the files if you want to look whats going on there:

 

https://dl.dropboxusercontent.com/u/22676624/pyroRendering.hipnc

https://dl.dropboxusercontent.com/u/22676624/pyroSim.hipnc

 

And I've managed to make one more sim and play with shader. I like the shader, but it's not what I had in mind. I feel I'm very close to my goal, but dont know how to achieve it. 

 

https://vimeo.com/110759728

[Diego A Grimaldi]

There are tons of great topics on this and the SideFX forums about shading and rendering pyro.

 

Here are some of the best:

 

http://forums.odforce.net/topic/17376-napalm-explosion-pyrofx/

http://forums.odforce.net/topic/18397-get-rid-of-mushroom-effect-in-explosion-and-add-details-in-the-opening-frames/

http://forums.odforce.net/topic/16879-pyro2-render-passes-help/

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=30370

 

Also I did this test a while ago:

 

 

 

I'd be happy to share my hip if you like.

Just FYI in my opinion  Pyro is extremely hard to master and slow as hell to render with good details. That's what I've experienced so far. And a lot of what you wanna accomplish in your pictures require a good amount of comp work as well.

 

Hope that helps!