CGTalk - HairSystem 1min render "render current frame", 20+ min in batch commandline

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mswertfager

11-13-2009, 04:51 PM

Morning all,

I am an independant student/filmmaker working on a 15 minute short now for over four years (sometimes full time sometimes part). Anyhow my lead character made years ago in Maya 6.5 and 7, has all the trimmings...including a rockin hair doo which the chicks dig (11 hairsystems of heavily stylized curves, mustache, ETC.) I would really like to avoid remaking it...as it would be a day or more to recreate and clean up (no interweaving of hairsystems to avoid shadowing artifacts, yadda yadda yadda.) . Maybe you can help me figure out this prob.

Basically, the char&hair renders in about 1 min in scene...but when batch/command line rendering downstream frames it is around 20 min+ each frame (that is a frame 700). Each frame duration increases the further down the timeline I start the renders, as you might expect there is also an hour runup when rending on the command line, but not when rendering the current frame from within Maya when at frame 700.

TESTS, ALTERATIONS - with minimal or no effect:
- All harisystems set to Static, Collision to Off, Hair Dynamic start frames set to frame 10,000
- Set scene to original Unit of Measure which he was created in (Inches)
- Hide Hair (prob still persists)
- Remove character set (this did drop the command line rendering from 20+ min to 11min...though in scene it renders at 1.3 min...so still a magnitude of almost 10)
- Removed cache's (no change occurs)
- Removed the Hairsysystems (fixes the command line rendering prob...confirming this is a hairSystem issue)
- Upgraded to 12 GB RAM, 64 bit machine (not-maxing out the Ram)
- Upgraded to Maya 2009 (no resolve)

* Below is a repost from trying to solve this with this char in 2005, it has more details.

-------------------------------------------------------
(Posting from 2005 - no resolution)

I'm experiencing an odd rendering effect due to my scenes hairSystem.

PROBLEM:
When I command line or batch render the scene at later timeframe frames (eg. frame 157 through 300), the Time for Frame Render is 3 mins but its taking 40+ minutes preceding each frame rendering. This is with the HairSystems -hidden- via a layer. However, when rendering inside Maya "Render Current Frame" its only 3 mins, with no delays preceding the rendering.

Oddly, rendering from frame 1 via the command line, each frame is only 3 mins with no delays preceding each frame.

I tracked this down to the hairSystems, as if I delete them, the scene renders via the command line in a timely fashion at the later time frames (eg. 157 through 300).

Any Ideas?
-Michael

Relevant info:
- Created hair in Maya 6, Maya 7, rendering in Maya 2009
- Rendering in Maya Software (command line below)
REM Render -s 157 -e 305 -pad 3 -cam cam_Shot07 -alpha 0 -im Shot07v1 -of tga shot07.ma
- Replaced memory on the system
- Reproduced on another computer with Maya 7

mswertfager

11-14-2009, 10:51 PM

Cause found...the pfxHair (despite it being set to static) was conflicting somehow with the fireplace fluid dynamics.

- With the pFX hair removed, the command line rendering starting at 700 works fine
(45 sec/frame)

- With the fluid dynamics removed, the command line rendering starting at 700 works fine
(30 sec/frame)

- Both fluid dynamics and pFX hair present, the command line rendering starting at 700 is severely hampered.
(20 min/frame)

Deleting the Fluid cache (initial frame) and recreating it worked.

Note: Fluids had a cached starting frame. The hairSystems did not have a saved cache.

-Michael

jdraks

11-15-2009, 11:11 PM

I had a issue with the batch rendering taking way longer than the viewpoint render. I searched around and found that it had to do with the render batch options. Set the number of threads to like 4 or 8 depending on your system. Make sure the CPU is at 100 during batch rendering.

mswertfager

11-16-2009, 03:27 PM

Thanks for the feedback jdraks.

n is set to 0 using all four processors. Fully utilized...

It was some sort of conflict between the paintFx hair and the Fluid Effects cache...Once I removed the initial frame cache for fluid effects, renders dropped from 20 mins a frame about 1 min a frame.

The only remaining challenge is that after I recreated the cache with nCache it worked fine for two batch renders...but once I reloaded the scene. It came up again...So, I deleted the fluids all together...all is peaceful again. I'll try recreating the fluid effects and see if that helps...if time permits on the project.

-M

I had a issue with the batch rendering taking way longer than the viewpoint render. I searched around and found that it had to do with the render batch options. Set the number of threads to like 4 or 8 depending on your system. Make sure the CPU is at 100 during batch rendering.

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