Is there a script that can rasterise an alpha channel from artwork to create a matching mesh? I notice on the Cycles thread that it is better to use real mesh rather than transparency for things like leaves (where there are lots of possible instances).
I thought that bmesh would be well suited to that sort of thing but I don’t know how you would access the alpha as a shape to trim too? Unless you made a bump map and cut away the excess.
I only had an alpha keyed piece of art in .png format. So I impoted the image as a plane (addon) subdivided a couple times, then added modifier > subd simple to 6 levels. Used the leaf map with a color ramp (to white) and used that for modifier> displace map. Applied both and deleted all the extraneous verts.
Finally I used Bmesh > dissolve and Bmesh > smooth verts to clean up the edge.
You can trace any pixelbased image with inkscape (shift+alt+b) [PATH>Trace Bitmap] and create a SVG from it. Save it as plain! SVG, not inkscape SVG and import to Blender, extrude it and ultimately convert it to a mesh.
Actually is a bit messy, but works a lot better than someone would expect.
It seems like the Vertex Group Edit Modifier should be able to sample a Vertex Group based on an image (or the alpha channel of an image), but I don’t get it to work.
It wouldn’t be a very elegant solution in this case (using the VGroup for a Mask Modifier), but could be very useful in other situations.