Actually I, too, have a question about drawing lines:
How can I draw a line which will emit particles in a specifically defined direction, or to follow a path? For example in creating Saturn’s ring. I tried deleting vertices from a plane and got perfectly nice lines, but can’t control the direction of particle emission. Thanks very much for your help and patience.
Hmmm… I’ve never used a “line” to emit particles before. Particles are emitted in the direction of the normal, which requires a face. Since a line has no face, it opens up some ambiguity regarding the direction of the particles. Instead of a line, why not use a very long and thin plane. That way you can rotate it and control the direction of it’s normal.
Better yet, if you are very new to blender, why not try some more basic projects to find your way around first.
bob is right.
YOu can do that with a very slim rectangle, which has a normal.
Use ‘Face’ button to make particles be emitted by faces.
Of course it is impossible to have particles travel in circles, so you better do particles whith no speed at all and have youe rectangle move in a circle leaving a particle trail.
Personally I prefear to make the ring as a mesh and let that ring emit particles. Easier to animate.
I happen to have an example:
http://reblended.com/www/s68/movies/ring.avi (6Mb, you are warned)
http://reblended.com/www/s68/movies/ring-lq.avi (0.9Mb, low quality, but faster to download)
Stefano
Thanks for the suggestions. In the case of making the small rocks in Saturn’s rings, you’re right, it seems best to move the emitter or use dupliframes to make them and then just have them rotate as objects.
However, why do you say “Of course it is impossible to have particles travel in circles?” What is the limitation there?
I took this as a bit of a challenge and actually did get them to move in circles (or at least appear to): Make a lattice with a lot of x elements (I used the maximum of 64). Warp the lattice 180 degrees. Set up the emitter to send the particles through the lattice. Set the lifetime of the particles so they disappear when they reach the end of the lattice. Then make an identical emitter and 180 degree lattice and put it together with the first lattice to make a circle. Set the Start time for the second emitter to one frame after the time the particles from the first emitter reach the end of the first lattice. It works well and looks pretty good, but is a pain to set up, partly because once you parent an emitter to a 180 warped lattice, it become very tricky to position the emitter properly (positioning the emitter before parenting doesn’t help because the emitter moves when you parent it).