light streaks

Hi,

I would like to make the following :

Each vertice of a mesh “emits light”.
By moving the camera along the object, the emitted light creates a light streak.
(like when using a camera with a slow shutter speed)
Note, it is the camera that moves, not the object.

Ideally I should be able to change the “lifetime” of light :slight_smile:
How could I create such an effect ?

thank you.
Geoffrey.

halo material and vector blur
sorry i don’t have much time to reply with a full post I’ll finish it in the evening when i come back if someone else hasn’t explained it

well for each vertice you could use the duplicate vertice and add let say a littel sphere with some halo on it
then with Blur node in composite this should do some light streaks

happy 2.5

back. No need for spheres (halo material essentially creates a light dot thingy on every vertex)
just make the object to have a halo material then use vector blur with a really high Blur value (that will adjust the length of the streaks)

I don’t think you’ve ever done this…

Halos don’t have geometry… you don’t get zbuffer or a vector pass with them…

Using dupli objects and vector blur (or even just a single object) vector blur only goes up to 2… it’s only for simulating motion between 2 frames.

You can overlay previous frames in teh sequencer to get long streaks… maybe use an additive blend…

doing this you’ll want a pass that it just teh streaks on black.

hmmmm good point, my mistake

if you want this blur effect blenderguru has a nice tutorial for making rain with streaks
have a look and try this method it may work

another indirect way would be to use particules to make light streaks !
see wip for Aurora making but would probably over do it may be with very long ligh streaks! LOL

happy 2.5

Do it in post-production…

http://www.kdenlive.org/users/granjow/writing-light-graffiti-effect

Thanks all for the interesting replies.
I am using Halo material, perfect solution for my problem !
And indeed, I am doing the rest in post production.

Thanks again :wink: