Low Houdini Fluids Speed

[ITdreamer]

Hello

Maybe I don't understand something, or maybe doing something wrong.

But it seems to me that Houdini fluids are much slower than Maya fluids.

Fluid Container 30x30x30 with a smoke emitting from a simple sphere in Maya simulates in realtime 25fps, but in Houdini exactly the same Fluid container simulates 4-5 times longer.

Maybe someone can explain me why it is so, or what I am doing wrong.

I am a fan of Houdini, but this low speed became a big problem for me when I needed to create a realistic look fire with smoke. Sad Sad Sad Sad

[ITdreamer]

I've just made another test.

Default Smoke Fluids Container (divisions 30x30x30) with a sphere as a source in it.

It takes 6 seconds to simulate 100 frames in Maya 2008.

And exactly the same scene in Houdini takes 40 seconds to simulate 100 frames.

So sad that I want to cry !!!!!

[symek]

I've just made another test.

Default Smoke Fluids Container (divisions 30x30x30) with a sphere as a source in it.

It takes 6 seconds to simulate 100 frames in Maya 2008.

And exactly the same scene in Houdini takes 40 seconds to simulate 100 frames.

So sad that I want to cry !!!!!

Maya Fuids are great but simplified non-physical model (no pressure computation for example). Houdini fluids are designed for much more accuracy results. The point is in optimisations. Simulate lower resolution and add details with texture noise for example. Check out this year Houdini Siggraph presentation or, if you can, wait for another version of Houdini... (H9.x)

cheers,

sy.

Edited October 19, 2008 by SYmek

[Aearon]

appart from that, keep in mind that the design of the fluid in houdini tools has a totally different focus. it's really geared towards flexibility which always costs some speed. this has been confirmed by sidefx people numerous times.

i think it's true that for a lot of basic stuff (which is all everybody uses most of the time) a more closed and speed optimized could be better. but houdini can do all that stuff, and also quite a bit beyond that. and yes don't forget that with houdini's workflow you can build many things on top of a very basic fluid sim without longer simulation times.

to generalize this more you could also say that working on a 100.000 poly character model is probably faster in maya, but then maybe simulating and rendering a crowd of thousands of those is a job better suited for houdini and mantra then maya and mr.

bottomline is use the tool that is better for a specific job.

Edited October 19, 2008 by Aearon

[ITdreamer]

Well, I agree with you in some parts, and it is great that houdini is so accurate, BUT BUT BUT !!!

I need to burn a house, and the density of fluids grid is much more higher in different parts of the house (80x240x80 for example).

And I HAVE to do it in Maya, because I don't have days for waiting when Houdini will simulate (accurate, but slow result).

And it is also hard control the stuff when everything is slow. It takes 95% time to wait, and 5% time to control the fluids behavior.

And how from this we can create realistic results? On low divisions of container we can't feel and see the details, which are very important for final results.

I love Houdini very much, I like it's proceduralism, but I'm so sad . I need to create a great effect and I have to do it in another application.

[symek]

I understand your frustration and I didn't mean that we should treat an accuracy is an excuse for not optimizing things in Houdini (which is in many respects terribly slow). But in fact a genius of Maya Fluids is that it IS a game engine highly adopted to it.

Definitely check these links:

http://forums.odforce.net/index.php?showto...9&hl=fluids

http://forums.odforce.net/index.php?showtopic=7548&st=0

As far as I know this is already implemented in Houdini just waiting for a premier.

[ITdreamer]

Thanks for all materials and links !