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"Slate3" 3D Short Film-making Research Project - Newsletter 5 - 01 Feb 2009

The Strange Story of "Ambient Flick"

Video A - Carpark with "Ambient Flick"

Video B - Carpark with "Ambient Flick" removed

Joys and Dangers of "Auto Keyframe" - applies to most 3D Software with Animation

"Auto Keyframe" is usually the default mode.  It means that most of your changes will cause keyframes to be automatically written into the animation timeline. 
IF you are not at the beginning of the timeline THEN Tweens will also get automatically generated.

This is a quick way to work, but it can also have traps.
You MUST rewind to the beginning BEFORE you make any design changes, including lighting changes and camera view changes, else you will get an accidental animation which can be very weird and frustrating.  I have tried working with "Auto Keyframe OFF" but that can cause the opposite problem of failure to save animation.  After trying them both I like "Auto Keyframe ON" best but I give the warning "TAKE CARE".

Carrara has the "Director's Camera" which gives you the freedom to move around to check details during the animation without causing any camera movement animation.   The "orthographic" cameras: "top", "bottom", "front", "left" and "right" are also safe from accidental camera movement animation.

With Carrara, in most cases you can fix accidental animation by finding the extra unwanted keyframe in the animation sequencer, then deleting that keyframe.   My most common accidents are in the "Default Camera" timeline.

In "DAZ Studio", the "Auto Keyframe" is always on and there are no timeline tracks for separate elements.  The very simplicity can make "DAZ Studio" fast in a very quick-and-dirty style but it is almost impossible to fix errors.  "DAZ Studio" works best making very small-chunk animations to feed into a video editor where you can CTRL-Z or even start again without feeling much pain.

Back to "Carrara":  Some of the elements that can animate themselves are not obvious and can be difficult to find and fix.  One of the worst cases I have ever suffered of accidental animation was in this carpark scene:

The lighting changed on the walk cycle giving a flick-flick-flick effect as Victoria walked through the building.  I spent an entire Sunday afternoon removing lights in turn then re-rendering to try to find out which light had accidental animation but nothing changed and all the lights had clean timelines with beginning keyframes only.  Early on I checked the Scene Ambient Light but I could not see any level changes as I moved the playhead.  What I did not realise was that I had Bezier Tweening on and the effect of that was to keep the ambient light level steady through most of the walk cycle then suddenly increase it at the end.  There is no sequencing timeline track for "Ambient Light" but eventually, after about 4 hours of pain, I found an extra unexpected keyframe in "Scene Effects" at the very bottom of the animation sequencer.

Click on the extra keyframe to select it, it turns yellow, then press the Delete key.

For those of you now asking, 'what and where is "Ambient Light"?'  Here is some quick info.
"Ambient Light" is even?y spread over all surfaces in the scene, a little like the lighting we get outdoors on a cloudy day.   You get access to the Ambient Light control by clicking on "Scene" at the top of the "Instance" tab panel - half-way down on the right-hand side of Carrara.  The Ambient Light control then appears under "Scene � Effects" at the top right.
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BUT THEN - - - - the story of the "Art Factor!"
We had a meeting for this film project on 15 Jan 2009, and I explained to the others how I had this problem and fixed it.   And what did they say?  They said they liked the scene better with flicking ambient light!  That it gave the scene extra mood and interest to have it looking like there is a faulty light flickering!  So the earlier video is the one we will use. Am I happy?  Yes!   I feel that the (long) time I spent "fixing the mistake" was useful in giving us 2 videos to compare to have an interesting discussion.  This knowledge of how to fix did not get used for this scene but it may well be useful in other scenes.