How can I emit smoke from just the outline of a model? I know my way around Blender a bit, but I'm in no way an expert. What I am trying to do is have a humanoid mesh that is invisible, but have smoke emit from it's silhouette only, not it's volume. Is there a way to generate a mesh on just the outline of a model similar to backface culling with solidify modifier so that the smoke only generates at those locations?

I tried to keep the question short, but let me know if anything is unclear.
Thanks!
Use the mesh as emitter. Use vertex painting to paint the “silhouette” as a vertex group. Set vertex group in smoke. Set volume to 0.