The Tips in detail

 "Alphablending?"

Trying to add some effects on a video that you have, specificaly you want (ie.) to add the "blade" of a lightsaber in a video shooted by a videocamera... you know typical starwars f/x.

So you use alpha blending to blend the video, with the blade but you get a strange result: the glow from the lightsaber leaves a "trail" behind it, it's like rendering the frames one on top of the others, and it is not like motion blur, it's from the begining to the end of the movement, it just stays there in the whole animation...

You tried to use another blending method (pseudo aplha, or simple compose) but then the glow doesn't even render... You tried to use the glow (frame only) instead of "lens effects glow" but you still got that strange result... You even tried to remove the motion blur at all but to no avail...

I had the same problem... try this:

• Add an Image Input Event (the background avi)
• Add a Scene Input Event (the camera)
• If I remember well, now you should select the Scene Input Event and then add the Lens Effects: Glow. If it doesn't work, try putting it elsewhere.
• Click on the Queue tree (this selects all the events)
• Add an Image Layer Event (huh huh...)
• Edit that and select "Alpha Compositor" (This way the 3d scene will have an alpha channel that will be used with the background)
• Deselect all and add an Image Output Event (The final avi)
• Click on the Execute Sequence button to render.

from: Yirtne <yirtne@libero.it>