Hello. I've been getting the hang of houdini, but one thing I can't figure out is when I write out my sim using the ROP driver, My computer takes about a hour + for a frame at .05 divisions (I've rendered at .1, the quality wasn't the hottest), but when I look at my computer performance monitor my CPU and Ram are not being maxed out. I've tweaked some settings in the Cache Manager, but it doesn't seem to effect it.

I have 16 GBs of ram and only a total of 9GB are being used all to geather, computer running, houdini running, etc…

Any ideas on how to max out my computers performance?

Is there some render settings I should be aware of to get better quality?

Attached is a render (.1 divs @ 1:1 picture ratio), no post CC, any tips on making this look better would be GREAT!

hey hereacoon,
can you send a hip file so I can have a look…? hard to tell like that for the performance part and the render settings !

lari

Sure, thanks a lot!

ok … where to start!!

You're in a right direction but there are some things you might (always) want to consider. To optimize a sim, you may want to break it down into steps.
How about sim your RBD, write it as a bgeo and then use it as an emitter rather than sim both at the same time… the RBD sim won't take you much time by it self and it will leave your computational power to your pyro sim.

Another thing you may want to check is your source division size.
If you go in your Sphere > create_fuel_volume, in your scalar volume tab > settings tab the Division size is linked to the pyro division size… If your using the RBD just for driving the fuel, then you may delete the channel and set it to a lower division. In your case, since the size of the Sphere is big you don't need that much division.

Another thing is your scaling, what is the representation of your sphere in real life. is it the size of a soccer ball or a building… remember Houdini works by meter… If you put a box base flat to the grid, and set the size to 2 units it is the equivalent of 2m.

Concerning your mantra node, you have set the pixel sample to 12x12, which is really high (Higher values = higher render time).
set it back 8x8 for a start, and you may want to make the min max ray samples 6x12, as they act like min max iterations of your pixel samples.
You can also lower your noise level below 0.01… maybe something between 0.002 and 0.005 (lower values = more render time)
Volume Quality was by default which is 0.25 … 1 will match the volume step size, lower values will result in losing details.
Remove sample lock if your rendering the sequence.

As for the artistic side of it! what are you trying to achieve?
If your looking to achieve a dense explosion, check the shader in the file I posted last time
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=28149&highlight=videocopilotption=com_forum&Itemid=172&page=viewtopic&t=28149&highlight=videocopilot [sidefx.com]

It should give you an idea of what you can do with the shader.

Hope it helps!

lari

Lari! Thank you! This mean a lot to me, you help me a ton last time. Everything you said is great. At the moment I'm just trying to get the hang of houdinis pyro. so for the scale and what I'm trying to create I should have figured that out .

Thanks again!

Hey Lari, great info, been using it all is going well. How ever my houdini still won't let me use all my ram or CPU when ROPing out the sim, any idea on how to fix this?

Thanks again for the post.

I might be mistaken, but ROPs shouldn't be more about transferring data from RAM (or directly from sim) to disk? That's the part that takes time, it's not actually computational intensive. But for example, a large scale pyro can take easily more than 10gb per frame, and regardless of the hard disk's speed that's something that's going to take some time.
Not 1 hr per ROPfram'e as you're experiencing, but if you already cached out the sim, there's no reason why it should take that long. Unless you're like ROPping out the entire scene every frame somehow.

akabane
Not 1 hr per ROPfram'e as you're experiencing, but if you already cached out the sim, there's no reason why it should take that long. Unless you're like ROPping out the entire scene every frame somehow.

Yeah Idk whats up. How long does it take you to ROP that out at .05 divisions? I get through the first 35 frames fast then it takes 1+ per frame.

Hey hereacoon,
The first frames are fast because your sim starts at 35 when the RBD hits the ground. On my machine the first frame of Pyro (frame 35) takes a while to initialize but that's normal. Your Pyro container is huge, so at initialization (before the resize container kicks in) it has to create all the data for this box at every single voxel.

At frame 36, the resize container kicks in and the sim start running much faster.

What I would do! If your camera will show you the entire explosion(not cropped at the sides or the top) then it is worth to scale your container at the same size of your emitter (leave some padding) and in your resize_container > Max Bounds …
2 options …
first : uncheck the Clamp to Maximum, this will get your container to scale with the density until it dissipates. It can be very heavy at the end of your sim if you don't know when your density is dissipating.

second: keep it checked, set it to manual and define a big sized box and that will be the limit of pyro. ( I prefer that option!)

Now for the performance issue, can't tell why its not using all the CPU's, same on my machine but its not going slower from siming without writing to disk. If you have Allow caching to disk and you already played a couple of frames before it will write them down fast as bgeo. Else, it will sim every single frame.

lari

Thanks again Lari! I'll try these suggestions out when I get some time.