“Afterglow” or “fade away” node for the composition nodetree.
Before reading this please mind you that this is nothing i personally need in any way, but it certainly sounds very cool to have and i just wanted to put this somewhere before it’s lost in the attic of my brain.
At first I wanted to put this directly into the suggestion page in the wiki, but I believe there are quite some people here that might have critics & suggestions.
The effect is very similar to the motion/vector blur effect, but takes the whole thing to a different (and in some ways more extensible) level. It may also need less CPU power. But it’s not a replacement for motion/vector blur.
I know that this may be already possible (i bet it is somehow) with the exiting compoostiion nodes, but i never tried it.
Imagine a new composition node with the following properties:
A ‘texture’ that is the same size as the output node. I’ll reffer to this as the ‘buffer’.
Multiple inputs (objects&groups) that tells the node where (mask?) to look for the color&intensity values of them. An actual seperate node that gives you the mask layer of a specified object would be even better IMHO … see the end of this post.
An “intensity” value - This tells the node how fast the glow fades away from in the buffer.
Maybe a “delay” and other values are needed as well here to control the fading behaviour better. I’ll exclude them from this proposal to make it simpler
Each composition-frame the buffer will be darkened by a certain value (depending on “intensity”) and the color & intensity of the given objects&groups will be applied to the buffer.Examples
With this node you’ll be able to create very long light trails.
A still landscape and a moving bright light in front of a camera with long exposure time. Here you’ll see a light-trail after the light.
Very long lightsaber trails.
Anime-style light trails of car/motorcycle-lights that last unrealistically long.
“Object Mask” node
And as mentioned above a composition node that takes as imput a object&group name and outputs the alpha mask would be quite a bon in a lot of cases (no extra scene or other tricks). You can combine multiple of these mask with existing RGB-nodes.
Ok, i’ve run out of coffee now. Cheers,