Mantra performance problem

[shiz]

First things first:

– This is not a “why Mantra is so slow” topic. In fact, Mantra is my first renderer, so until now, for what I read, it seems pretty fast and good.

– I came from a digital product design background and I’m really new to 3d and Houdini.

– I’m using a MacBook Pro for learning which I know its definitely not the best machine to work with 3d stuffs. (Specs: Mid 2012, 2.3Ghz i7, 8GB RAM, GeForce GT 650M 1GB)

So after this (not so happy) presentation, lets talk about my problem: I was doing a tutorial from Niels Prayer about how to make a geometry react from an audio file and after that I've tried to render a sequence of 860x540 images. I waited 14 long hours for about 12 secs of video. Is this normal for my computer specs?

I forgot to cache the geo, but I don’t know if this could be a great factor to get a faster render, could be?

I've read some topics about Mantra settings from Odforce and SideFX forum and found some interesting tips about how to get better and faster rendering trying to get down the pixel sample values, increase the max ray samples and tweak the noise level to an acceptable value.

So I’ve attached a hip file with my Mantra settings, and my machine can render this frame in about 3:13 min. This is current the best I can do in terms of speed and quality. Do you guys can check it out my file and see what I can do to get a faster render? Please feel free to hit me with tips on how to get the best of Mantra and Houdini in general.

Thanks a lot.
Cheers,

render-test.zip

_render_test_1.exr

[Thomas Helzle]

Sounds pretty normal to me.

On my 6 core i7 from 2013 @ 4.1 GHz it takes 1:16 Minutes.

Mantra is very bad at finding thin lines and only raising the main Pixel Samples will help there, not the Ray Variance Antialiasing since if the first samples don't see the line, it does not search further (same with Depth of Field and Motion Blur). So your 6 are at the low end already, not much you can do about speed otherwise.

Subsurface Scattering is very slow and noisy in Mantra, so if you can get away without it, you should.

The only real options to get faster renders is using a GPU renderer like Redshift and get a machine with some powerful graphics-cards like GTX 1080 TI or Titans, have several machines work on it with network rendering or using a cloud render service like Gridmarket etc. A fast main machine of course helps as well ;-)

You get 3 Houdini Engine licenses for free with Indie which can be used for network rendering and network simulation in case you have other machines available. Complicated to setup but works.

Mantra seems to be mainly geared at studios with powerful renderfarms, for the solo freelancer with limited renderpower it is quite hard to do animations with it.

Cheers,

Tom

[shiz]

Thanks for the answer, Thomas.

I turn off Subsurface Scattering and now is 30 seconds faster.

Weird thing: It seems my render time is a little unstable. When I was doing this topic, I've got a 3:13 min render, now is 4:24 min (both with SS on). Same conditions, frame, file and settings. Is this normal too?

Thx again man,

Shiz

Edit: btw, I loved your work. I think code is poetry too and I love to work with Processing and Javascript. Very inspiring!

Edited February 5, 2017 by shiz

[Thomas Helzle]

Well, make sure your laptop is plugged in and on highest performance settings and not overheating, otherwise it may throttle performance.

Also make sure nothing else is going on in the background that sucks up CPU cycles. Otherwise the differences should be in the range of a couple of seconds only. But sometimes it makes a difference if Houdini/the computer is started fresh or running for a long time, but it shouldn't be that much of a difference.

Edit: Oh, and I found "preview" rendering slower than non-preview rendering - the hopping around of the buckets slows final speeds down it seems. It's a bit less so when you set Update Time to a higher number - I use 30 as my default.

Also make sure you're not running out of RAM. I always thought 32 GB are a lot but with Houdini it's actually very little. I'll buy another 32 ASAP...

Thanks a lot for your nice words - I guess many Houdini artist can relate to that :-)

Cheers,

Tom

Edited February 5, 2017 by Thomas Helzle