   Particle Systems - 3D stroke
  I'm just wondering on how this was implemented:http://trapcode.com/in_action/3dstroke_intro.htmlI think it's particle systems and rendering using blobs but I'm new to the topic and i'm not quite sure. I'm looking to re-implement from scratch using a different programming language.Also this is basically a general question on how to get a 3d effect like that and map it to 2D.Thanks   
  It's not rendered using a particle-system, I'd say it's rendered using bezier curves (wiki for this). Then there's probably some f(x) function at each key-point that determines the thickness of the line.As far as saving to a 2D image, google for offscreen rendering and PBO's.Cheers!/Robert   ;  I think you're right, and I started sketching it out:http://www.student.cs.uwaterloo.ca/~hbizira/3dstroke.jpgI would draw a bezier curve using user supplied control points. Then to get the tapered effect I just create two new curves based on the original curve and then offset them using the normals at the points (see the above link, the new curves are the dotted ones). Then I would just fill in the area enclosed by the curves.This was all well and good, then I saw this example:http://www.trapcode.com/movies/organic.movI'm confused as to how they get the fill color to look like that. This makes me thing they're using particles or something to achieve that effect.;  Don't really see how you can see a particle system out of that video... I can't see anything that would resemble the usage of such a system... In fact i don't even see how it's different than the other video you posted except that the color fades off quicker from the center of the line;  You probably shouldn't use Bezier; it has nice mathematical properties, but it does not intersect its control points, except the terminal ones. You would want that property to get the best results.The use of particles to do the rendering would be fine; just use the thickness function to determine particle size, instead of all that silliness with curve offsets. The problem would be finding the balance between too many particles (inefficient overdraw) and too few particles (unsmooth gaps).   