13 replies to this topic

[jesschaco]

Hi all!
I just started digging into Houdini pyro. As a practice, I want to duplicate this fire spreading shot in the video (starting at 00:19).
https://www.facebook...100268402351436

From the look of it, I see three different rings of fire expanding from the same ignition point(the outer blue fire, second less intense ring of fire, and the last ring of fire burning more intensely)So I have been using different particle emitters for each ring.
What I am having trouble is the second ring of fire where the fire streaks lick and moves along the surface of the floor. Any idea how this could be done? Or maybe my logic is totally wrong here? Any help would be much appreciated!!! Thank you!

[ChristianW]

Well I would start with a sop solver to get attributes spreading over your ground plane.
A leading edge to use for colouring blue later and a radial ramp controlling fuel or something like that.
You could tweak the normals from the sop solver to point out from a center point, making the flames apear to be pushing away from center, maybe putting that into a velocity field with the SOP Vector Field:
http://www.sidefx.co.../sopvectorfield

Messing with different attributes propagating into the pyro solver from the original sop solver should give you quite a bit of control on how it looks.
Hope that helps.
C

[jesschaco]

Thanks Christian! I will give it a try!

ChristianW, on 21 July 2012 - 05:30 AM, said:

Well I would start with a sop solver to get attributes spreading over your ground plane.
A leading edge to use for colouring blue later and a radial ramp controlling fuel or something like that.
You could tweak the normals from the sop solver to point out from a center point, making the flames apear to be pushing away from center, maybe putting that into a velocity field with the SOP Vector Field:
http://www.sidefx.co.../sopvectorfield

Messing with different attributes propagating into the pyro solver from the original sop solver should give you quite a bit of control on how it looks.
Hope that helps.
C

[bunker]

You don't need any particles or sopsolvers
Think "real word": put some gasoline on the ground and add the temperature from a matchstick,
and watch it burn :  flamefront.hipnc   1.93MB   212 downloads

jesschaco, on 20 July 2012 - 02:13 PM, said:

Hi all!
I just started digging into Houdini pyro. As a practice, I want to duplicate this fire spreading shot in the video (starting at 00:19).
https://www.facebook...100268402351436

From the look of it, I see three different rings of fire expanding from the same ignition point(the outer blue fire, second less intense ring of fire, and the last ring of fire burning more intensely)So I have been using different particle emitters for each ring.
What I am having trouble is the second ring of fire where the fire streaks lick and moves along the surface of the floor. Any idea how this could be done? Or maybe my logic is totally wrong here? Any help would be much appreciated!!! Thank you!

[jesschaco]

Thanks Julien, this is awesome!

bunker, on 22 July 2012 - 12:03 AM, said:

You don't need any particles or sopsolvers
Think "real word": put some gasoline on the ground and add the temperature from a matchstick,
and watch it burn : flamefront.hipnc

[jesschaco]

couldn't figure out why i made an exact duplicate of the settings and couldn't produce the same result. I had to change the field in resizing container to make it work.(weird)~but got it resolved! Please disregard this file. Thanks again Julien!

Attached Files

•  fire.hip   1.26MB   87 downloads

Edited by jesschaco, 24 July 2012 - 04:42 PM.

[mms]

And how to render

bunker, on 22 July 2012 - 12:03 AM, said:

You don't need any particles or sopsolvers
Think "real word": put some gasoline on the ground and add the temperature from a matchstick,
and watch it burn : flamefront.hipnc

and how to render it?Result is just black screen. I tried to add import DOP node and import fields node, the I applied a shader, but nothing.  I modified your scene, I hope you don`t mind.
I`m writing my bachelor thesis about fire and smoke sim in Houdini, so it would be really good to know how to work with own fields and render it.

Attached Files

•  flamefront.hipnc   2.01MB   0 downloads

Edited by mms, 10 January 2013 - 07:23 AM.

[xmetallicx]

Hey i looked at your file,

I deactivated density and fuel in your DOP I/O node and your volume will render. Since it seems that won't really need it for render anyway.

Tweaked the shader a little just to get the color.

- Joel

Attached Files

•  flamefront_332_joel.hipnc   2.01MB   76 downloads

Edited by xmetallicx, 11 January 2013 - 01:40 AM.

[mms]

Thank you very much! Now I`ll try to understand why it should be like that.

[Skybar]

I'm having some trouble with this. It all works fine really, I even managed to create the fuel from a texture.

However, the fuel won't "exist" outside of the resizing bounding box. On the first frame it resizes around the heat, which is in the middle. The fuel then gets cropped to that first resize, so when the bounding box grows larger the fuel isn't there. I sort of solved it by continously emitting more fuel, but that kinda destroys the effect.

I may add that it does work if I make the bounding box large enough and turn off resizing, but that is quite inefficient. Also, the hip-file from here works just as it should - but I created it myself using 12.5 and yeah, trouble. Anyone have any ideas?

[cubiccube]

Inside the gasresize DOP, remove fuel from the "gasresize_fire" field list

[Skybar]

cubiccube, on 10 April 2013 - 03:18 PM, said:

Inside the gasresize DOP, remove fuel from the "gasresize_fire" field list

Oh wow, I would never have figured that out. Thank you!