Why are my render times flip-flopping???

[Michael J. Brown]

I'm running several animation sequences, one of which is respresented by the attached .jpg. In this particular sequence, i'm using Logorithmic E.C. with G.I. set to default levels. F.G. is set to draft. 13 lights, 3 of which have raytraced shadows and 1 with shadow mapping - the others have shadows turned off. Frames are being rendered to .jpg.

 

There is no motion in this sequence. All that changes is the camera lense (zooming inward). Therefore, I've set my F.G. to use the saved map.

 

Here's the weird thing though. My frame render times take turns alternating between (around) 2min41sec and 4min50sec. WHAT UP??

 

I understand a few seconds fluctuation between frames. But for them to go from low to high to low to high just doesn't seem to make any sense. Can anybody shed some light on this?

 

 

Thanks:(

[Macer]

First of all, if you are just zooming, I would render one higher resolution image and create the zoom effect in post - much faster.

 

I don't know what could be causing the difference in render speeds - what area is taking longer? Is it a certain area of buckets or around a particular bit of geometry?

 

Could it just be that at certain angles the reflection of light off the plants or another reflective surface are more complex?

 

You really need to figure out where its taking longer - you may have to watch/time a few frames.

[Michael J. Brown]

First of all, if you are just zooming, I would render one higher resolution image and create the zoom effect in post - much faster.

 

Well, actually, there is some animation that occurs late in the sequence. The door slides open (as the camera zooms in tight) and bright white light floods out. So, unfortunately I would not be able to do it in post.

 

I don't know what could be causing the difference in render speeds - what area is taking longer? Is it a certain area of buckets or around a particular bit of geometry?

 

Could it just be that at certain angles the reflection of light off the plants or another reflective surface are more complex?

 

You really need to figure out where its taking longer - you may have to watch/time a few frames.

 

Yeah, I've watched many frames. It definately is taking a bit longer on the plants due to reflections and glossiness. But even on the quicker rendering frames it slows down on the leaves. It for some reason though, the ENTIRE frame (on every alternate frame) takes almost twice as long to render as the one before it. Dropping all reflectance makes no real difference. The frames render quicker, but every other one is still taking twice as long as it's alternate.:confused: