This is exactly why most productions will use renderers geared toward 
utmost speed.
In vfx production raytracing is more often than not a last resort, or 
only used for very select elements in a shot.
The speed you can get out of modern scanline/REYES renderers these days 
is absolutely mad. Couple this with a well thought out pipeline based on 
reusability of cached render data, and the whole process of rendering 
thousands of entirely cg frames starts to seem realistic! (also a farm 
of a couple of hundred processors kinda helps).

A lot of the effects that raytracing grant you can be either:
-faked using creative empirical methods
-baked out to point or rasta data cahes to be re-used for subsequent 
renders (effectively turning an expensive ray call into a simple map 
look-up ( which has further benefits if you use a mip-mapped data format 
( these can exist for 2d and 3d data! ) ) )
- or restricted to specific passes, so that when you do need to 
raytrace, you contrive your scene to trace against an absolute minimum 
of participating geometry.

The other (vital) aspect to production renderers is programmable shading 
languages. Having very low level conrol over shading lets you tune the 
shading of a scene to do the bare minimum
of shading computations to get a frame out at an acceptable quality and 
time frame. And with programmable shaders, you aren't locked into 
someone else's idea of what a certain effect should look like, or how it 
should be calculated. Nearly every shot in every sequence on every show 
needs to be tweaked and tuned uniquely to make sure you get the 
bang-for-the-buck into the image, and the image out on time!

benpee
www.rsp.com.au

EagleSun wrote:

>
>
>BOOM!  Oh how I wish all you guys's comments were true and that I was
>joking... unfortunately, Jeberger guessed correctly (sortof...)
>
>I found a parameter that can lead to a perfect render of earth, it's called
>"sample".  I entered some blow-out number and clicked on "Run" to render
>the image.  And yes, I forgot to turn on anti-alias.
>
>Despite its small size, this render took 1 HOUR to render a simple 256^2
>image!
>
>This gets worse...
>
>I'm working on a movie where the screen resolution will be 1280 x 720.
>Assume I don't need to anti-alias (which I do), I'll render a single frame
>for about 14 hours!  Since the scene should be about 2 minutes long, where
>the frame rate will be 24 fps, that's going to take me 40 THOUSAND HOURS!
>In simple terms, this translates to 1,687.5 days, or 4 years and 7 months..
>assuming optimal and continuous rendering conditions 24x7 on a 2.6 GHz
>system!http://www.planetside.co.uk/terragen/sneakpeek/boulder.html
>
>
>  
>

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