viddy | 11 years ago | 4 comments | 2 likes | 3,173 views
Using video layers within BT can result in some *really* cool effects, but you may also quickly realise how frustrating they can be too (based on v8.04 pro).
Here's a few tips that have so far helped me overcome some of the video layer quirks during the past few days...
= Keep Shows Short and Sweet =
The main underlying issue with video layers is that you currently have no control over *when* their content (the actual video) starts...
Each video layer that's used in a show effectively has its content 'autoplay' at *frame 1* (right at the start) of the timeline...
So if you have a video layer appear on screen 4 seconds into the show, then 4 seconds of its content will have already played by the time it's seen on stage.
Likewise, a 2nd video appearing in the scene at 10 seconds will already be 10 seconds into its content.
This makes using video pretty fiddly, because you may need to 'pad' the start of a video in order to get the correct timing. And then if you need to adjust a keyframe in the show, the timing gets thrown out again.
Because of this it's best to 'chunk' video use across multiple shows, using just *one* video layer per show (unless the content of the video is just 'filler' and not timing-dependent).
Those chunks can then be brought together by the next tip...
= Make The Most of Playlists! =
Playlists work just like those on your mp3 player: they make it easy (in most cases!) to connect chunks/patterns of animation together by combining/rendering several BT shows together...
...which is *very* useful for using video layers, due to the issue explained above.
Plus, playlists are your best friend when combined with the power of *xml files*...
= Overcoming XM-HELL =
Don't be scared away by the 'dynamic content' (via xml files) section of the BT user guide...
...it's *really* valuable in being able to draw in text, images, and *video* to your shows in order to make them *easily reusable* for different content/clients...
Behind the jargon, the 'xml' file just provides a simple way to tell BT what text, image or video to use in a show, rather than telling it *inside* the show itself (in the layer's properties.
It also enables you to 'loop' through a single show any number of times using different content for each loop.
The benefit is that you'll create shows/patterns you can easily re-use *many times over*. All from changing some text and image/video locations inside a small file.
But there is currently one *big* sticking point when using dynamic content with *video*...
Let's say you create a simple animation using video:
it's a tv screen that swoops into view, plays its video content, and swoops back out. You want it to swoop in and leave 3 times, each time playing a *different* video.
The best way to do this is to create the animation ONCE (as one show) and draw in dynamic content for the video from an xml file. The xml file just tells BT to loop through that SINGLE show *3 times* - using a different video each loop...
Perfect! BUT here's the problem:
Even though BT loops through the show 3 times with 3 different videos, it starts playing the content of *all 3 videos* right at the *start* of the *very first loop*.
So - although the preview looks ok, the actual rendered movie is all out of sync (the content of each animated tv screen is not what you wanted)...
= The Solution =
One option is to make all 3 video files the same length as the BT show - but that's time-consuming and messy.
A better solution is to add your single show *3 times* to the playlist (as if you were playing an mp3 track 3 times in a row on your ipod), and attach a separate xml file for *each video* to each repeated show.
That way, the final rendered movie is created as expected, without the timing issues.
Having just re-read it myself, this post may not make too much sense to you (yet!) :) ...
...but if you decide to work with video layers i'll almost GUARANTEE that you'll encounter these restrictions and quirks at some point (sooner than later)...
...and hopefully some of this post will then prove useful :)
In a future update it would be great to see the video layer features enhanced (at least to determine when it's content begins).
It would certainly open the door for this great little program to punch *even further* above its weight.
And thanks again to the BT team for such a useful app.
Thanks for the tips.
JimH, 11 years ago
Thanks for taking the time to post all of these great tips.
GreenfishPete, 11 years ago
Thanks viddy for the detailed video layer tips
Eddie, 11 years ago
Thank you viddy, this is a very useful tip for all of those BT-user who made already experiments with the videolayer. Is it possible for you to post a short BT file, so everybody can see what you mean. One picture say more then 1000 words.
orlando, 11 years ago