PDA

View Full Version : Best technique for animations with no moving objects?



JeffrySG
06-19-2009, 05:59 AM
I'm getting ready to render a bunch of animations that will have no moving objects or lights at all. There will only be camera movements. Think along the lines of animated product shots or arch viz interiors.

What's the best technique to get the fastest renders?


There will be reflective surfaces
There will be soft shadows
There might be raydiosity (90% chance)
There might be transparency
There might be animated texture maps
They will probably be between 10 and 30 seconds in length


Also, how does this change if there are some small object movements during the animation? For example: a door on a toaster might open during the animation. Does that completely change the setup?

Thanks for any suggestions or tips.
Cheers!
Jeff

flakester
06-19-2009, 06:45 AM
My personal favourite would be mitchell filter, 5 pass with adaptive sampling on - set to 0.05 or so, up the AA passes if you have DOF or large amounts of movement. Photoreal motion blur isn't usually required unless things are moving quite quickly or you want a filmic look.

For radiosity, I'd recommend reading Excepts guide on all things to do with this; for best looking results for a particular scene and the best method(s) for animation. http://www.except.nl/lightwave/RadiosityGuide96/ though chances are that you may have read it already.

Or, there's always fprime if you have it.

Render out to an uncompressed (or lossless compression) image format sequence (24/32bit TGA / PNG / RGB) and create your video sequence files from these afterwards.

These are just my opinions, I'm sure others will have different (and most likely better for some outcomes) solutions.

Hope that helps, Dude.

--
flakester

JeffrySG
06-19-2009, 08:05 AM
Thanks for the input flakester... :)

I should have been more specific I guess too. I was specifically wondering if there is any ways to render much quicker by things such as - burning all of the lighting into the scene, or caching all of the raydiosity, etc. things like that. If nothing is moving what are the things that I can do to quicken the render times? As compared to an animation that has movement in it?

Also do you find it's quicker to use the AA at 1 and lower the AS Threshold amount? I usually find this to be true. I tend to lean towards Box / Blue Noise on my settings too....

biliousfrog
06-19-2009, 08:57 AM
You'll want to stick with fixed rather than blue noise for animation otherwise you'll get flickering as the sampling pattern will be constantly changing.

I prefer to do as much in post as possible. If you're using DoF, it would normally be faster to render a seperate depth map and do the blur in post. The map can also be used to add depth fog or haze too. If you only have a single object moving by a small amount, I'd consider rendering that element seperately and compositing it afterwards. The GI in that area might not be 100% accurate but it might be good enough to the untrained eye.

If you have very small objects such as hair, fur, grass, distant railings etc. you might need to render at 200% and scale down to prevent flickering caused by the objects moving between pixels. If you do, you can reduce the AA.

Caching will speed things up but I haven't played with it often enough. There was a video (from siggraph I think) that showed a scene with cache'd radiosity and changing the light colours updated the bounced light instantly as the GI was calculated and not the actual colours. As Flakester said, go through the Except guides.

Sometimes it is possible to fake the bounced light reasonably with standard lighting and just using background radiosity or AO to fill the void. It's quite good practice anyway to get the lighting perfect before using GI to add the cherry on top...AO is often good enough. Again, that is something I'd prefer to do in post with a seperate AO render with either white or grey objects and BG radiosity or non-interpolated FG.

JeffrySG
06-19-2009, 09:39 AM
^thx for the info... I'll make sure I use the fixed rather than the blue noise... :)