Hi,
Not entirely sure how it's all supposed to blend together in the end, but if I wanted fading trails on top of a video and the trails can be one colour I would:
Setup:
- Allocate an FBO
- Clear it to black
Draw:
- Bind this FBO
- Draw semitransparent black rect, (this gives you the fade)
- Draw your particle in white
- Unbind
- Draw the video
- Use additive blend (and colorize it with whatever colour you have set with ofSetColor) or a shader to blend the trails FBO on top.
There'll be a way to do it with alpha as well, but the caffeine hasn't really hit yet so it's escaping me.
