Multiple Instances of T2

Started by Themodman101, December 10, 2011, 05:24:13 AM

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Themodman101

Tangled universe said :

""Also, since thread-scaling is not optimal I would render with 2 instances of TG2 which both use 4 cores. Especially on big projects/animations this could save a significant amount of time.
There's always the GI issue though. GI padding adds quite some rendertime so using that too much might cause the gain to be lost quickly.""

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What i'm wondering is how you can get this to work, since you cant keep any Object Populations the same over 2 instances of the program right? Then you would have undulation in your tree's cause they would be different Propagations.

has this been fixed somehow?

dandelO

The populator uses the 'seed' value to keep instances in position while other blend shaders are used to lay instances based on that seed. There should be no deviation between instances over another TG session or open program instance.
I can't remember there ever being this issue with objects, I remember a time that the water shader didn't save its seed and that would have made this problem happen but that was years ago. I rendered my Light Breeze HD version over two instances because it worked out better to rearrange render bucket sizes and get the scene rendered much quicker by running two frames at a time instead of one. I say try it, the populations should stay in place... :)

digitalis99

I don't think you'll have any problems.  With the few jobs I've sent to my render farm with objects, populations, and more...the only problem I've run into is the GI lighting problems with animation.  The seed values "stick" across the rendering nodes, so that's not a problem.
Pixel Plow :: Render Endlessly :: http://www.pixelplow.net

Themodman101

Okay cool, I never thought of checking the populations Seed to see if its the same.. cause everytime I open my scene it has to repopulate the Vegitation objects. Is that unusual?

jo

Hi,

Quote from: Themodman101 on December 10, 2011, 08:49:55 PM
Okay cool, I never thought of checking the populations Seed to see if its the same.. cause everytime I open my scene it has to repopulate the Vegitation objects. Is that unusual?

No, it's normal. TG2 doesn't save the positions of items in a population, if it did the project files would be a lot larger. It's procedural, which means it's generated mathematically at when the program is running.

Regards,

Jo

Oshyan

Also TG2 scales well up to at least 8 threads now, so unless you're running a dual Xeon setup or similar, with 16+ threads it's probably more efficient to use a single instance.

- Oshyan

Themodman101

awesome!! thanks guys, so even if it repopulates as long as its the same seed even on a different PC it will be consistant.. Coolieo this fixes most of my problems then.

One last question, what causes frames that are rendered in sequence for animations to save as a plain white file? instead of said image like it should be? it doesnt do it when I save the frames manually.

Oshyan

Perhaps you're looking at the "extra" output files, which are alpha-only images at present. They are only saved out if you had Output Extra Images checked, and they should be alongside the main output images.

- Oshyan