Coin reflexion effect and possible Vegas bug

TorS wrote on 3/28/2007, 6:16 AM
In a video sequence where a 2 euro coin is tossed into a swimmingpool, I have faked reflexions while the coin turns in the air. It looks good.

Vegan text generator was used, with a dot. Don't use Arial, its dots are square. I used the shortest possible keyframe. The first one has the dot, accurately positioned, the next has no dot.

See it here (856 kB wmv)

A BUG? When the second keyframe was created from scratch - and had no placement ajusting (reasonable thing to to because nothing shows up anyway) it looked OK in preview, but not after rendering. There I got dots in wrong positions. After lots of trial and error I found out that the second keyframes with no dots influenced the placement in the first keyframes in render, but not in preview.

I had to delete the second keyframe, copy the first to the second position (so the placement setting were identical), and then delete the dot. (Some of you may get what I'm saying here.)

Anyway, I like the effect.


Spot|DSE wrote on 3/28/2007, 7:58 AM
Tor, could the speed of the keyframe have been causing the dot to be falling on one or the other field, offsetting its position?
TorS wrote on 3/28/2007, 8:23 AM
I doubt it, because the coin and reflexion were too far apart - and sideways, too.

I recovered a version with the fault.
See it here (856 kB vmw)
Jay Gladwell wrote on 3/28/2007, 8:43 AM

Oh... the problem is clear to see! The coin was moving faster than the speed of light, hence, the reflection was lagging behind.


TheHappyFriar wrote on 3/28/2007, 10:11 AM
looks like you're missing a keyframe.

To have a 1 frame "highlight/flash" like you're doing you need three keyframes:

one the frame before, current & after.

before = blank
current = settings you want
after = blank

blank = nothing. Could be size = 0 or a combo of an FX & transparency, whatever.

is that what you did (you need 3 keyframes for every flash).
TorS wrote on 3/28/2007, 11:10 AM
The only difference between the example in the first post and the one further down is that in the upper, the second keyframe has the same placement setting as the first.

And like I said, they both worked well in preview.
Chienworks wrote on 3/28/2007, 4:34 PM
Actuall if you use the "hold" setting on the blank keyframes, you'll only need two for each flash.