Houdini moving sphere with pyro - flame sometimes work

[mo22]

Hi all,

I am quite new to Houdini and I want to ask a question, I want to make the sphere in my scene to move in the z direction as a fire, not just as a sphere.

This is what I do:

- put RBD ground plane

- put sphere

- change sphere into a RBD object

- put the pyro - flame effects

The thing is, weird enough that it sometimes work and other times it doesn't. And when it works, and then I close the file and when I want to continue my work, it doesn't work anymore. I always got this container box full of the yellow-ish color but the fire is no where to be found. I am a bit desperate now since I have been remake the scene over and over again for the fire simulation.

Please help!

Thank you!

[mangi]

Hi are you catching the sim to disk ?

What version of Houdini are you using

What grafic card & what is the settings in your 3d View

mangi

Edited April 10, 2013 by mangi

[mo22]

Hi,

My graphic card is AMD Radeon HD 6770M 512 MB

I am using Houdini 12.5, and hmm, yes caching to disk with memory : 5000 and I only use the default 3D view.

Thank you

[ryew]

It may be a problem with your source, your resize settings, the fields being displayed . . . there are many possible causes - If you can post the .hip file, it would be easier for the friendy people on odforce to help you

[mo22]

Hi,

Oh yes, I am attaching my file here.

So the idea is that I want to have a fire shaped in a hand going through the pillars (with collision). But since I tried it with the hand model, it becomes so slow and I also cannot see the fire, only the white smoke around it, so I want to build the sim with the sphere first and then will replace it with the hand later when I have already get the fire as how I want it.

So in this file, it is only the sphere - fire with the pillars and i put one of the curve for the collision.

I hope someone can help me

Thank you!

bg.hipnc

[mo22]

I have now an updated file where in this file I tried to turn of the cache simulation at the DOP Node, and it seems that the fire shows but only if I am inside this DOP node.

and it works outside DOP if I hide my sphere node..

bg.hipnc

Edited April 11, 2013 by mo22

[traiano]

Hi

Your pyro container wasnt following properly the Sphere, see now that the container is tracking the sphere movement.

I also resized the container for better optimisations.

The problem about sometimes working and sometimes not is about going back and forth without properly caching. In that case just reset the Autodop simulation, go to Frame 1., give a desired Divisions amount to the Pyro, Go to Manual and then to AutoUpdate mode and everything will work fine.

I added some notes for you to check.

bg_martin.hipnc

Edited April 11, 2013 by traiano

[traiano]

Basically the problem here is the Pyro Container. If it stops working, just give a bit more padding to it and play again it will work fine.

[mo22]

Hi traiano,

Thank you, I checked the file but I don't get the one in the import_pyro_build, where should i cache it exactly? at the "output file" of the rop geometry node? if so, I tried that and save it on my disk, but then it shows the fire for frame 1 but when I play it the fire is gone. I also edited the padding for the pyro container also no luck..

[traiano]

First of all turn off OpenCL in advanced tab in Pyro.

I made you a Rop for you to cache fields, density fuel heat and temperature. Cache bgeo.

[mo22]

Hi Traiano,

hmm yes so I changed the pyro and also the open CL also changed the size of the container. But it is still the same, fire only on the 1st frame, when I play it it's gone did i do something wrong?

EDIT:

now I changed the lower and upper padding to 10 (for testing) and the fire is there but it the container stops after around 20 frames but the sphere keeps going. and when I changed the padding to 5, fire is gone

and if I put it on 8, it has fire but only until frame 82 and then it's gone

Edited April 11, 2013 by mo22

[traiano]

I just saw that you have 2 import_pyro and you only need one. So here is the new file. it works perfectly inside or outside import_pyro

you can dive in this import_pyro and cache out to disk the simulation, note that i turned off unnecessary fields to import.

Set the divisions on Pyro as desired. before you cache.

bg_martin_ready.hipnc

[mo22]

Oh yes now I get what I did wrong, it works now, thank you!

I have another question though if you don't mind, I put the curve 7 for the collision, but I can't really see if it works for collision or not (the fact that it is hidden now and because it's so thin), so how can I see if it works?

Thank you

[traiano]

Dive into the geometry that you name 'curve7', in the fluid source there is a viz tab, you can set up a slice plane to view, i barely use this though.

[mo22]

Hi traiano,

I put the slice plane to show it but it doesn't really show up in the viewport and I saw no difference with the fire animation. Perhaps I have to make the curve thicker? but how to do that? or did I do something wrong here?

Thank youuu!