Friday, August 26, 2005

"Render, render, render, keep those movies renderin', renderhide!"

I've been spending the last few days rendering, in pieces for four or five hours at a time, turning off my computer so it cools down for an hour or so, rebooting and begining again. I got so bored last night that I made an image Xia (to your left - click it to enlarge). Visit the webpage for more information about this image. It's interesting, I feel so suppressed by long term projects that in the midst of them I have to create little projects to satisfy that creative sense of urgency.
I have finished all of the scenes of my project (as far as I know - this doesn't mean that changes won't be requested - or modifications required after viewing the completed render - I am expecting there will be). I hit the message boards upon realizing my completed scene was much too large to be able to render in its entirety (over 30 hours of rendering) and I subsequently learned that rendering as individual tga or png files is the preferred alternative. The golden rule is "never render to .mov or .avi" - unless of course it is a small sequence like the examples currently on my website. This is the first project I have completed that is several minutes long (equals 5395 frames).
Distraction notification - I just searched my email box for correspondence related to this project, trying to determine how long it took me to create these 3 minutes, it looks like I started in March. 5 months (but I'm not done yet). It looks so simple and quick when the movies are viewed...... but in the background the work is really, the polar opposite.
At any rate, rendering my scene in the tga or png format (I chose tga for the lossless quality) will save each frame individually, so that if I crash (and I often have from over working my system during renders - even for the smaller scenes), I will not lose the whole thing like I would if it was a .mov file, I will still have every frame up to the point of the crash. Indeed during my first run of rendering this scene, I did crash (around frame 7 hundred something), I spotted that good ole' "delayed write" error that I've become so familiar with. I shut down my system for a rest - rebooted and every frame previous was still in tact. I now know not to render the output size of this scene up to a length of 700 frames, but to stop at a lower number. I also did a test compilation of these files from Combustion in a 2D composition mode - the 7 hundred frames I tested rendered very quickly, so I know that when I am done rendering from Max that I have a solution for gluing these individual files together. I'm not there yet, but I am beginning to see the light at the end of the tunnel...


Anonymous Anonymous said...

Yup... render to PNG from max and then let combustion be your tool to change color correction, etc, and then render to avi, mov, etc from Combustion.

That's my workflow too. Now rendering to PNG sequences can be higher file sizes, but it is worth the flexibility. And I put together two barebones systems myself to use backburner to speed up renders. For $1000 I put together two 3.0 Ghz P4 systems (with hyperthreading), both with a gig of ram and similar graphics cards.

I used eBay and to buy all the parts. Then bought a netgear "switch" some Cat6 cables and hooked it all up. The key I was told is to get your systems to be similar so that the frames don't have abnormal color shifts.

I was also told that if you mix and match processors it can really be way off. Because an AMD system will "calculate" mathmatically different than a Pentium system. So things like Particle Flow and other rendering calculations will be processed differently and then you could end up with sequences with color shifts between frames. (and with particle flow you will have total chaos).

Since I created this little mini 3 PC render farm I've been able to speed up renders dramatically. Rather than having to wait 3 hours for a render I can use all three to render the same project in about an hour.

And you can't do this using AVI or MOV files. Only when you render out to sequences (PNG, TGA, etc).

-Michael J

10:37 AM  
Blogger Gina said...

Yes, I have already set up my own wireless network (it's Netgear as well - 95$ at Fry's) although originally for the purpose of swapping files from system to system. I have three computers hooked up to my network, two of which have backburner. I would have to install another version on my third system to make the render farm worth it (I also have another system I could throw on - although it's a different operating system, it's 98 while my others are XP - are there any known problems with this?). Network rendering was something I investigated while debating the best route for this rather large project render. I was not aware of the compatibility of processors, thank you for sharing that useful information. I believe all of my processors to be Intel.
I've noticed that one of the computers has a hard time hanging onto the network connection when it is in another room, which is a bit odd considering that the other room I am referring to is also home to the laptop I am using right now which does not have this problem.
Although if I place the problem computer back by my network switch next to my master system, it seems to keep the connection better. I don't know if this would be an issue for render fails...
This is one reason why I didn't use a render farm, although I had more primary reasons, one was that I was told that due to my multiple large materials (some up to 5GB via a plentiful of morpher slots) that the network rendering would not be as efficient (what are your thoughts on this?) and second, I wanted to use my other system for something else while rendering.
My tgas are averaging around 1.08 MB each - I am currently up to frame 4601 so as you can imagine this folder is very large at 4.80 GB. I am a little concerned about which compression method would be best for my final compiled movie, especially considering that the animation is mostly involving fine text and small objects within the materials - I have to be careful about compromising the text when compressing. This movie will also probably be shown at conferences so not only does it need to be large enough for the projector view, but also small enough for the user to have loaded on their system - which is probably has more standard system specs...

2:56 PM  
Anonymous Anonymous said...

Some of the issues you mention I've not dealt with (large files for morph, win98 or network dropping).

As for the final output. Well I guess it depends on what it will play on and required FPS. I like Sorenson Video Pro 3 as a quicktime mpg4 output. Of course you could go mpeg2 (DVD-Video) if needed as well.

This is more a matter of final output and what it will run off of for presentations and the compression will squash down the file sizes considerably. And your file sizes using PNG for me is consistent with what I've seen.

Michael J

3:43 PM  
Anonymous Anonymous said...

Something that you may like to experiment with, if you have the time. I know very little about the rendering software you are using, but some CAD software, which does massive amounts of calculation, actually runs faster if you turn HT (Hyper Threading) off. Of course, this comment is total meaningless unless you are using a Pentium IV with HT! A reasonably quick test would be to take something that you've previously redered, say in fifteen minutes, and see how fast it is both with HT turned on and off.

12:38 PM  
Blogger Gina said...

Last night I installed the trial version of Sorenson Squeeze - using the Quicktime medprog setting and it compressed a 576 file into a pretty lossless 8.76 file. Amazing.... this was enough to convince me into getting the full program. Wish I would have done this before I sent the approval disks out!

2:14 PM  
Blogger Paul said...

Hi Gina, may be you did it intentionally, the Chinese characters on Xia's body are flipped. While the word on her arm means "happiness", it usually mean "good fortune" or "fortunate". There are two characters on the yingyang shape. The top one is "love" and the bottom one is "forever".

Nice work! What software do you use?

5:26 PM  
Blogger Gina said...

Hi Paul- thank you. My primary software programs are 3DS Max and Combustion.

8:55 PM  

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