Transparent render

Hi all
How can I achieve a transparent background for a small 250 frame animation of a golden key dropping and swinging back and forth with a glaring light behind the key.

It that has to glow/glare at a particular frame and dull the glare at the end of the animation.
I used a 1 pixel star for the glow but don’t know how to get it to switch off and on at certain frames.
My daughter wants to use my animation on her opening screen of a game she is working on.
many thanks

the transparant background is easy - just render the animation out with an alpha channel

for that you need to use a format that supports alpha - like PNG
then click the RGBA button - this saves the images with the alpha information
(want to see the alpha?? when you render a frame - press a - that shows you in black and white what the alpha channel looks like)

to get it to turn off and on you can animated the alpha value of your glowing object

eg if you want it to glow for 10 frames and turn off for 5 and glow for 10 more
set a key frame for the alpha value at frame 1 to full(1.0) again at frame 10 to full
at frame 11 set a key frame to (0) - at frame 15 set it at (0) and frame 16 set it to full again

I find this easier to do in the IPO window (you can use constant interpoloation for this example to make it easier too)

here is the render panel to explain the RGBA


Also, in F10 use Premul or Key instead of Sky.


Hey! Another Roger!!! Welcome to BA. I hope you have fun with Blender.
In Blender, everthing that is not a mesh is actually transparent. Even the blue background, even though it is blue, has an Alpha value of 0. which means that if you use the VSE and AlphaOver your key thing on top of a background, that blue will go away. The trick, like waylow said, is to use the PNG format that will save that alpha channel.

I didn’t know that
ta Fligh