How do you convert an alpha to mesh shape?

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.

Sorry if this is the wrong place mods.

If it’s SVG, or can be converted into SVG, there is an importer for it bundled with blender. (http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Import-Export/SVG)

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.

Thanks for that everyone.

Dude, almost 4k posts and you aren’t familiar with the support section?

moved…

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.

You’re right, I shouldn’t post while working. Sorry all. Please move this thread if reqd